diff --git a/src/core/Game3.lua b/src/core/Game3.lua
index c0539d1d..8598835e 100644
--- a/src/core/Game3.lua
+++ b/src/core/Game3.lua
@@ -15,6 +15,7 @@ local MapIds = require("src.core.game3.map_ids")
 local Profile = require("src.core.game3.profile")
 local Runtime = require("src.core.game3.runtime")
 local Audio = require("src.core.game3.audio")
+local Warm = require("src.core.game3.warm")
 local Options = require("src.core.game3.options")
 local Dataset = require("src.core.game3.dataset")
 local Display = require("src.core.game3.display")
@@ -117,6 +118,10 @@ function Game3:_enterField(session, reason, opts)
   -- pokefirered/src/fieldmap.c:100
   Runtime.start(nil, self, session, { reason = reason or "new_game" })
   Map._nextEnterVia = nil
+  pcall(function() require("src.core.game3.prewarm").session(session) end)
+  local Syms = package.loaded["src.import.gba.syms"]
+  if Syms and Syms.reset then Syms.reset() end
+  collectgarbage("collect")
   if fieldCallback then require(fieldCallback).execute() end
   if reason == "continue" then
     if lazyReq("src.core.game3.profile").family(session) == "rse" then
@@ -755,6 +760,8 @@ function Game3:update(dt)
   local okP, errP = pcall(function() lazyReq("src.render.Pipelines").update(dt) end)
   if not okP then s9log("pipelines", errP) end
   pcall(function() lazyReq("src.core.DiscordPresence").update(dt) end)
+  local okW, errW = pcall(Warm.step)
+  if not okW then s9log("warm", errW) end
   Game3.stepGC()
 end
 
diff --git a/src/core/Music.lua b/src/core/Music.lua
index 404c6189..6be8d797 100644
--- a/src/core/Music.lua
+++ b/src/core/Music.lua
@@ -23,8 +23,8 @@ local function applyVolume(src)
       fading = state.fade ~= nil,
       optionScale = volumeScale,
     }
-    local ok, Game = pcall(require, "src.core.Game")
-    if ok and Game then
+    local Game = package.loaded["src.core.Game"]
+    if type(Game) == "table" then
       local ow = Game.overworld
       if ow and ow.player then
         ctx.x, ctx.y = ow.player.cellX, ow.player.cellY
diff --git a/src/core/game3/audio.lua b/src/core/game3/audio.lua
index 9bad18dc..0a8fc0d1 100644
--- a/src/core/game3/audio.lua
+++ b/src/core/game3/audio.lua
@@ -9,6 +9,7 @@ local Mix = require("src.core.game3.m4a_mix")
 local Player = require("src.core.game3.m4a_player")
 local SE = require("src.core.game3.se_ids")
 local Song = require("src.core.game3.song_ids")
+local Warm = require("src.core.game3.warm")
 local ffiOk, ffi = pcall(require, "ffi")
 
 local Audio = {}
@@ -817,6 +818,7 @@ Audio.SE_LOOP_MAX_SEC = 2.5
 Audio.SE_ONESHOT_MAX_SEC = 30
 
 function Audio._seRawClear()
+  Audio._cryCache, Audio._cryCacheN = nil, 0
   Audio._seRaw = {}
   Audio._seRawFrames = 0
   Audio._seRawTick = 0
@@ -919,6 +921,55 @@ function Audio._seSourceFor(id, rawL, rawR, master, pan, mono, loop)
   return src
 end
 
+local function bake_se(id, opts, memoable)
+  local slot = { voices = {} }
+  -- SE must run the M4A sequencer (SE_SELECT is CGB pulse, not voice0 PCM).
+  local ok = Player.start(Audio._pack, Audio._cache, slot, id, { forceSeq = true })
+  if not ok then
+    warn_once("se:" .. tostring(id), "SE " .. tostring(id) .. " missing")
+    return nil
+  end
+
+  local loop = opts.loop
+  if loop == nil then
+    -- SE_LOW_HEALTH and any track with GOTO before FINE are hardware loops.
+    loop = (id == SE.SE_LOW_HEALTH) or Audio._songHasGoto(slot)
+  end
+
+  local loopBody = loop and opts.loop == nil and id ~= SE.SE_LOW_HEALTH
+  -- pokefirered/src/battle_anim_special.c:1200
+  local cut = ((loop and not loopBody) or id == SE.SE_EXP)
+  local maxSec = opts.maxSec
+    or (cut and Audio.SE_LOOP_MAX_SEC or Audio.SE_ONESHOT_MAX_SEC)
+  local rawL, rawR, loopStart = Player.bakeSlot(slot, {
+    raw = true,
+    maxSec = maxSec,
+    stopOnGoto = loop and true or false,
+    loopBody = loopBody,
+  })
+  if not cut and opts.maxSec == nil and type(rawL) == "table"
+    and #rawL >= math.floor(Mix.SAMPLE_RATE * maxSec) then
+    warn_once("selen:" .. tostring(id),
+      "SE " .. tostring(id) .. " hit the " .. tostring(maxSec) .. "s bake ceiling")
+  end
+  if memoable then Audio._seRawPut(id, loop and true or false, rawL, rawR, loopStart) end
+  return loop and true or false, rawL, rawR, loopStart
+end
+
+function Audio.prewarmSe(id, priority)
+  id = SE.resolve(id)
+  if id == nil or not Audio.isReady() then return false end
+  if Audio._seRaw and Audio._seRaw[id] then return false end
+  local info = Audio.songInfo(id)
+  if info and info.kind == "fanfare" then return false end
+  return Warm.add("se:" .. tostring(id), function()
+    if Audio._seRaw and Audio._seRaw[id] then return end
+    local loop, rawL, rawR = bake_se(id, {}, true)
+    if loop == nil or loop then return end
+    Audio._seSourceFor(id, rawL, rawR, Audio._sfxVolume or 1, Audio.normalizePan(nil), Audio._mono, false)
+  end, priority)
+end
+
 function Audio.playSe(id, opts)
   opts = opts or {}
   id = SE.resolve(id)
@@ -938,42 +989,14 @@ function Audio.playSe(id, opts)
   Audio._stopSePlayer(mplay)
 
   local memoable = opts.loop == nil and opts.maxSec == nil
+  if memoable then Warm.flush("se:" .. tostring(id)) end
   local hit = memoable and Audio._seRawGet(id) or nil
   local loop, rawL, rawR, loopStart
   if hit then
     loop, rawL, rawR, loopStart = hit.loop, hit.rawL, hit.rawR, hit.loopStart
   else
-    local slot = { voices = {} }
-    -- SE must run the M4A sequencer (SE_SELECT is CGB pulse, not voice0 PCM).
-    local ok = Player.start(Audio._pack, Audio._cache, slot, id, { forceSeq = true })
-    if not ok then
-      warn_once("se:" .. tostring(id), "SE " .. tostring(id) .. " missing")
-      return false
-    end
-
-    loop = opts.loop
-    if loop == nil then
-      -- SE_LOW_HEALTH and any track with GOTO before FINE are hardware loops.
-      loop = (id == SE.SE_LOW_HEALTH) or Audio._songHasGoto(slot)
-    end
-
-    local loopBody = loop and opts.loop == nil and id ~= SE.SE_LOW_HEALTH
-    -- pokefirered/src/battle_anim_special.c:1200
-    local cut = ((loop and not loopBody) or id == SE.SE_EXP)
-    local maxSec = opts.maxSec
-      or (cut and Audio.SE_LOOP_MAX_SEC or Audio.SE_ONESHOT_MAX_SEC)
-    rawL, rawR, loopStart = Player.bakeSlot(slot, {
-      raw = true,
-      maxSec = maxSec,
-      stopOnGoto = loop and true or false,
-      loopBody = loopBody,
-    })
-    if not cut and opts.maxSec == nil and type(rawL) == "table"
-      and #rawL >= math.floor(Mix.SAMPLE_RATE * maxSec) then
-      warn_once("selen:" .. tostring(id),
-        "SE " .. tostring(id) .. " hit the " .. tostring(maxSec) .. "s bake ceiling")
-    end
-    if memoable then Audio._seRawPut(id, loop and true or false, rawL, rawR, loopStart) end
+    loop, rawL, rawR, loopStart = bake_se(id, opts, memoable)
+    if loop == nil then return false end
   end
 
   local pan = Audio.normalizePan(opts.pan)
@@ -1045,6 +1068,7 @@ function Audio._buildSeSoundData(L, R, master, pan, mono)
   master = master or 1
   local gainL, gainR = Audio._seGains(pan)
   local gl, gr = master * gainL, master * gainR
+  local warm = package.loaded["src.core.game3.warm"]
   local ptr
   if ffiOk and ffi and sd.getFFIPointer then
     local okP, p = pcall(sd.getFFIPointer, sd)
@@ -1068,6 +1092,7 @@ function Audio._buildSeSoundData(L, R, master, pan, mono)
       sd:setSample(i - 1, 1, l)
       sd:setSample(i - 1, 2, r)
     end
+    if warm and i % 4096 == 0 then warm.yield() end
   end
   return sd
 end
@@ -1338,6 +1363,67 @@ function Audio.waitFanfare(cb)
   if not Audio._fanfareActive and cb then cb() end
 end
 
+Audio.CRY_CACHE_MAX = 24
+
+local function cry_inputs(mode, pan, volume)
+  mode = tonumber(mode) or 0
+  local cfg = Audio.config()
+  -- pokeruby/src/sound.c:364
+  if cfg.cryModeMax and (mode < 0 or mode > cfg.cryModeMax) then mode = 0 end
+  local params = Sample.cryParams(mode, volume or cfg.cryDefaultVolume, cfg.cryModeOverrides)
+  return params, pan and pan ~= 0 and Audio.normalizePan(pan) or nil
+end
+
+local function cry_meta(slot)
+  local cry = slot and slot.info
+  if not (cry and cry.cryIndex ~= nil) then return nil end
+  local c = Audio._pack.index.cries[cry.cryIndex]
+  return c and Audio._pack.samples[c.sampleId], cry.cryIndex
+end
+
+local function cry_render(slot, params, pan, mode, volume)
+  local meta, cryIndex = cry_meta(slot)
+  if not meta then return nil end
+  local key = table.concat({ tostring(cryIndex), tostring(mode), tostring(volume), tostring(pan),
+    Audio._mono and "m" or "s" }, ":")
+  Warm.flush("cry:" .. key)
+  local cache = Audio._cryCache or {}
+  Audio._cryCache = cache
+  local hit = cache[key]
+  if hit then return hit.sd, hit.info end
+  local pcm = Sample.loadPcm(Audio._pack.samplesBin, meta)
+  if not pcm then return nil end
+  local sd, info = Sample.renderCry(pcm, Mix.waveRate(meta.freq), params, {
+    outRate = Mix.SAMPLE_RATE,
+    pan = pan,
+    mono = Audio._mono,
+  })
+  if sd then
+    Audio._cryCacheN = (Audio._cryCacheN or 0) + 1
+    if Audio._cryCacheN > Audio.CRY_CACHE_MAX then
+      Audio._cryCache, Audio._cryCacheN = {}, 1
+      cache = Audio._cryCache
+    end
+    cache[key] = { sd = sd, info = info }
+  end
+  return sd, info
+end
+
+function Audio.prewarmCry(species, mode, pan, priority)
+  species = tonumber(species) or species
+  if species == nil or not Audio.isReady() then return false end
+  local params, npan = cry_inputs(mode, pan, nil)
+  local slot = Player.startCry(Audio._pack, species, { pitch = 1.0 })
+  local _, cryIndex = cry_meta(slot)
+  if cryIndex == nil then return false end
+  local key = table.concat({ tostring(cryIndex), tostring(tonumber(mode) or 0), "nil", tostring(npan),
+    Audio._mono and "m" or "s" }, ":")
+  if Audio._cryCache and Audio._cryCache[key] then return false end
+  return Warm.add("cry:" .. key, function()
+    cry_render(slot, params, npan, tonumber(mode) or 0, nil)
+  end, priority)
+end
+
 -- pokefirered/src/sound.c:333
 function Audio.playCry(species, mode, pan)
   species = tonumber(species) or species
@@ -1350,10 +1436,7 @@ function Audio.playCry(species, mode, pan)
     noDuck = o.noDuck == true
   end
   mode = tonumber(mode) or 0
-  local cfg = Audio.config()
-  -- pokeruby/src/sound.c:364
-  if cfg.cryModeMax and (mode < 0 or mode > cfg.cryModeMax) then mode = 0 end
-  local params = Sample.cryParams(mode, volume or cfg.cryDefaultVolume, cfg.cryModeOverrides)
+  local params, npan = cry_inputs(mode, pan, volume)
   local doubles = params.mode == 1 or noDuck
   Audio._cryParams = params
   log(string.format("playCry species=%s mode=%d", tostring(species), params.mode))
@@ -1367,25 +1450,14 @@ function Audio.playCry(species, mode, pan)
     return false
   end
   Audio._crySlot = slot
-  local cry = slot.info
-  local meta = nil
-  if cry and cry.cryIndex ~= nil then
-    local c = Audio._pack.index.cries[cry.cryIndex]
-    if c then meta = Audio._pack.samples[c.sampleId] end
-  end
-  local pcm = meta and Sample.loadPcm(Audio._pack.samplesBin, meta)
-  if pcm then
+  if cry_meta(slot) then
     Audio._crySource = nil
     if not doubles then
       Audio._duck = 85 / 256
       Audio._duckHold = 2
       apply_bgm_gain()
     end
-    local sd, info = Sample.renderCry(pcm, Mix.waveRate(meta.freq), params, {
-      outRate = Mix.SAMPLE_RATE,
-      pan = pan and pan ~= 0 and Audio.normalizePan(pan) or nil,
-      mono = Audio._mono,
-    })
+    local sd, info = cry_render(slot, params, npan, mode, volume)
     if info then
       Audio._cryUntil = (Audio._cryClock or 0) + info.frames
     end
diff --git a/src/core/game3/battle/bg.lua b/src/core/game3/battle/bg.lua
index 95c6861f..ec006531 100644
--- a/src/core/game3/battle/bg.lua
+++ b/src/core/game3/battle/bg.lua
@@ -81,6 +81,21 @@ local function frlgSheetKey(env, id)
   return primary
 end
 
+function BattleBg.resolveOpts(opts)
+  local terrain = opts.terrain
+  -- pokefirered/src/battle_main.c:689
+  if terrain == nil and (opts.mapBehavior ~= nil or opts.mapType ~= nil) then
+    terrain = BattleBg.resolveFromBehavior(opts.mapBehavior, opts.mapKind, opts.mapType)
+  end
+  if terrain == nil and opts.mapKind then
+    terrain = BattleBg.resolveFromMapKind(opts.mapKind)
+  end
+  if terrain == nil then
+    terrain = BattleBg.TERRAIN.BUILDING
+  end
+  return terrain
+end
+
 function BattleBg.sheetKey(id)
   id = tonumber(id) or BattleBg._terrainId
   local env = BattleBg.env()
diff --git a/src/core/game3/battle/init.lua b/src/core/game3/battle/init.lua
index caa71f9d..c9a64ca9 100644
--- a/src/core/game3/battle/init.lua
+++ b/src/core/game3/battle/init.lua
@@ -679,17 +679,7 @@ function Battle.start(opts)
   end
 
   local BattleBg = require("src.core.game3.battle.bg")
-  local terrain = opts.terrain
-  -- pokefirered/src/battle_main.c:689
-  if terrain == nil and (opts.mapBehavior ~= nil or opts.mapType ~= nil) then
-    terrain = BattleBg.resolveFromBehavior(opts.mapBehavior, opts.mapKind, opts.mapType)
-  end
-  if terrain == nil and opts.mapKind then
-    terrain = BattleBg.resolveFromMapKind(opts.mapKind)
-  end
-  if terrain == nil then
-    terrain = BattleBg.TERRAIN.BUILDING
-  end
+  local terrain = BattleBg.resolveOpts(opts)
   st.terrain = terrain
   -- pokefirered/src/battle_bg.c:714
   BattleBg.setTerrain(BattleBg.resolveOverride(terrain, {
diff --git a/src/core/game3/battle/moves.lua b/src/core/game3/battle/moves.lua
index 433881d6..a7173770 100644
--- a/src/core/game3/battle/moves.lua
+++ b/src/core/game3/battle/moves.lua
@@ -48,8 +48,13 @@ function Moves.loadRomPack(cache)
   Moves._romLoaded = true
   local root = (Extract.CACHE_ROOT or "data/generated/gba") .. "/pokemon/battle_moves.lua"
   cache = cache or require("src.core.game3.dataset").cache()
-  local src = assert(cache:read(root), "pokemon/battle_moves.lua is not in the cache")
-  local pack = assert(load(src, "@" .. root, "t", {}))()
+  local chunk = Moves._romChunk
+  if not (chunk and Moves._romChunkCache == cache) then
+    local src = assert(cache:read(root), "pokemon/battle_moves.lua is not in the cache")
+    chunk = assert(load(src, "@" .. root, "t", {}))
+    Moves._romChunk, Moves._romChunkCache = chunk, cache
+  end
+  local pack = chunk()
   Moves._rom = assert(pack and pack.moves, "pokemon/battle_moves.lua has no moves")
   Moves._numByName = nil
   build_names()
diff --git a/src/core/game3/battle/ui.lua b/src/core/game3/battle/ui.lua
index 33b8e0aa..e4498081 100644
--- a/src/core/game3/battle/ui.lua
+++ b/src/core/game3/battle/ui.lua
@@ -243,7 +243,7 @@ function Ui.reset(opts)
   Ui._oldManSubstate = nil
   if Message and Message.isHeld and Message.isHeld() then Message.close() end
   if not Ui._headless then
-    local okC, errC = pcall(BattleChrome.install, nil)
+    local okC, errC = pcall(BattleChrome.ensureInstalled)
     if not okC and not chromeInstallWarned then
       chromeInstallWarned = true
       print("[game3/battle.ui] BattleChrome.install failed: " .. tostring(errC))
diff --git a/src/core/game3/battle_bridge.lua b/src/core/game3/battle_bridge.lua
index 37435a61..5018bab8 100644
--- a/src/core/game3/battle_bridge.lua
+++ b/src/core/game3/battle_bridge.lua
@@ -146,8 +146,8 @@ function BattleBridge.installWhiteoutIntercept(mod, game)
   end
   BattleBridge._whiteoutHook = onWhiteout
 
-  local ok, World = pcall(require, "src.world.gen2.World")
-  if ok and World then
+  local World = package.loaded["src.world.gen2.World"]
+  if type(World) == "table" then
     if type(World.whiteOut) == "function" and not World._game3WhiteOut then
       local prev = World.whiteOut
       World.whiteOut = function(self, ...)
@@ -398,6 +398,9 @@ function BattleBridge.start(mod, game, foe, opts)
   if not session then return nil, "no session" end
 
   BattleBridge.installWhiteoutIntercept(mod, game)
+  if not opts.headless then
+    pcall(function() require("src.core.game3.prewarm").battle(session, foe) end)
+  end
   if opts.wild and require("src.core.game3.profile").family(session) == "rse" then
     -- pokeemerald/src/battle_setup.c:417
     require("src.core.game3.rse.init").call("tv", "incrementDailyWildBattles", "IncrementDailyWildBattles", nil)
@@ -659,6 +662,9 @@ function BattleBridge.start(mod, game, foe, opts)
     local StayMessage = package.loaded["src.ui.game3.message"]
     if StayMessage and StayMessage.closeStay then StayMessage.closeStay() end
   end
+  if not opts.headless then
+    pcall(function() require("src.core.game3.prewarm").battleStart(startOpts) end)
+  end
 
   local function doStart()
     local ok, err = Battle.start(startOpts)
diff --git a/src/core/game3/dataset.lua b/src/core/game3/dataset.lua
index 1afd4edb..8fccf24d 100644
--- a/src/core/game3/dataset.lua
+++ b/src/core/game3/dataset.lua
@@ -376,11 +376,29 @@ function Dataset.mountExtractRoots()
 end
 
 local manifestLayouts = {}
+local lazyLayouts, LazyDef
 
 function Dataset.invalidateManifestCache()
   manifestLayouts = {}
 end
 
+lazyLayouts = setmetatable({}, { __mode = "k" })
+
+LazyDef = {
+  __index = function(def, k)
+    if k ~= "midLayout" then return nil end
+    local src = lazyLayouts[def]
+    if not src then return nil end
+    lazyLayouts[def] = nil
+    local blob = src.cache:read(src.rel)
+    local decoded = blob and require("src.import.gba.native_pack").decodeMidLayout(blob)
+    if not decoded then return nil end
+    local layout = require("src.core.game3.layout_native").fromDecoded(decoded, src.mapId, src.pair, blob)
+    rawset(def, "midLayout", layout)
+    return layout
+  end,
+}
+
 --- Bind LayoutNative handles onto map defs (FieldView needs midLayout).
 function Dataset.attachMidLayouts(maps, cache)
   if type(maps) ~= "table" then return 0 end
@@ -397,25 +415,28 @@ function Dataset.attachMidLayouts(maps, cache)
   end
   local attached = 0
   for mapId, def in pairs(maps) do
-    if def and not def.midLayout then
+    if def and not rawget(def, "midLayout") and not lazyLayouts[def] then
       local info = layouts[mapId]
       local rel = nativeRoot .. "/"
         .. ((info and info.file) or ("layouts/" .. mapId .. ".mid"))
       local blob = cache:read(rel)
-      if blob then
-        local decoded = NativePack.decodeMidLayout(blob)
-        if decoded then
-          local pair = (info and info.pair) or def.pair
-          def.midLayout = LayoutNative.fromDecoded(decoded, mapId, pair, blob)
-          local tw = decoded.trueWidth or decoded.width
-          local th = decoded.trueHeight or decoded.height
-          if tw and tw > 0 then def.width = tw end
-          if th and th > 0 then def.height = th end
-          if pair then def.pair = pair end
-          attached = attached + 1
+      if blob and #blob >= 16 and blob:sub(1, 4) == NativePack.MAGIC_MID then
+        local pair = (info and info.pair) or def.pair
+        local tw = blob:byte(11) + blob:byte(12) * 256
+        local th = blob:byte(13) + blob:byte(14) * 256
+        if tw > 0 then def.width = tw end
+        if th > 0 then def.height = th end
+        if pair then def.pair = pair end
+        if getmetatable(def) == nil then
+          lazyLayouts[def] = { cache = cache, rel = rel, mapId = mapId, pair = pair }
+          setmetatable(def, LazyDef)
+        else
+          local decoded = NativePack.decodeMidLayout(blob)
+          if decoded then def.midLayout = LayoutNative.fromDecoded(decoded, mapId, pair, blob) end
         end
+        attached = attached + 1
       end
-    elseif def and def.midLayout then
+    elseif def then
       attached = attached + 1
     end
   end
diff --git a/src/core/game3/field_effects.lua b/src/core/game3/field_effects.lua
index ed9b0cee..3597cbd7 100644
--- a/src/core/game3/field_effects.lua
+++ b/src/core/game3/field_effects.lua
@@ -146,7 +146,7 @@ local function drawFrlgReflections(camX, camY)
           for j = 1, #live do
             local obj = live[j]
             if not obj.hideReflection and obj.graphicsId and not obj.virtualId then
-              local spr = Ow.getDraw(obj.graphicsId)
+              local spr = (Ow.peekDraw or Ow.getDraw)(obj.graphicsId)
               if spr then
                 objectPoseOpts.frame = obj.customFrame
                 local frame, flip = Ow.pose(spr, obj.facing, Objects.walkPhase(obj), obj.stepFlip,
diff --git a/src/core/game3/field_effects_rse.lua b/src/core/game3/field_effects_rse.lua
index 1ca1be8b..4d80f3fb 100644
--- a/src/core/game3/field_effects_rse.lua
+++ b/src/core/game3/field_effects_rse.lua
@@ -682,7 +682,7 @@ local ghostPose = {}
 
 local function drawReflection(obj, gid, frame, hflip, x2, y2, camX, camY, ox, oy)
   local Ow = package.loaded["src.core.game3.ow_sprites"]
-  local spr = Ow and Ow.getDraw and Ow.getDraw(gid)
+  local spr = Ow and (Ow.peekDraw or Ow.getDraw)(gid)
   if not (spr and spr.quads and spr.quads[frame]) then return false end
   ox, oy = ox or 0, oy or 0
   local cx = (obj.moving and obj.targetX or obj.cellX) + ox
@@ -871,7 +871,7 @@ local function drawReflections(camX, camY)
           for j = 1, #live do
             local eo = live[j]
             if not eo.hideReflection and eo.graphicsId and not eo.virtualId then
-              local spr = Ow.getDraw(eo.graphicsId)
+              local spr = (Ow.peekDraw or Ow.getDraw)(eo.graphicsId)
               if spr then
                 ghostPose.frame = eo.customFrame
                 local frame, flip = Ow.pose(spr, eo.facing, O.walkPhase(eo), eo.stepFlip, ghostPose)
diff --git a/src/core/game3/item_use.lua b/src/core/game3/item_use.lua
index c63ac4b2..7b4ec871 100644
--- a/src/core/game3/item_use.lua
+++ b/src/core/game3/item_use.lua
@@ -47,7 +47,8 @@ end
 local function not_the_time(session)
   if require("src.core.game3.profile").family(session) == "rse" then
     -- pokeemerald/src/item_use.c:158 DisplayDadsAdviceCannotUseItemMessage
-    return (RomText.box("gText_DadsAdvice", { playerName = player_name(session) }))
+    -- pokeruby/src/item_use.c:146
+    return (RomText.box(is_rs() and "gOtherText_DadsAdvice" or "gText_DadsAdvice", { playerName = player_name(session) }))
   end
   return (RomText.box("gText_OakForbidsUseOfItemHere", { playerName = player_name(session) }))
 end
diff --git a/src/core/game3/m4a_player.lua b/src/core/game3/m4a_player.lua
index 2b65744b..839e9e84 100644
--- a/src/core/game3/m4a_player.lua
+++ b/src/core/game3/m4a_player.lua
@@ -590,6 +590,8 @@ function Player.bakeSlot(slot, opts)
     else
       idle = 0
     end
+    local warm = package.loaded["src.core.game3.warm"]
+    if warm then warm.yield() end
   end
   if #L == 0 then
     L[1] = 0
diff --git a/src/core/game3/m4a_sample.lua b/src/core/game3/m4a_sample.lua
index f57d7013..1551f652 100644
--- a/src/core/game3/m4a_sample.lua
+++ b/src/core/game3/m4a_sample.lua
@@ -181,6 +181,7 @@ function Sample.renderCryMix(pcm, sampleRate, params, opts)
   local gain = (tonumber(params.volume) or Sample.CRY_VOLUME) / 127
   local reverse = params.reverse and true or false
   local out = {}
+  local warm = package.loaded["src.core.game3.warm"]
   for i = 0, nOut - 1 do
     local g = env.gain(math.floor(i * frameRate / outRate)) * gain
     local acc = 0
@@ -196,6 +197,7 @@ function Sample.renderCryMix(pcm, sampleRate, params, opts)
       if acc > 1 then acc = 1 elseif acc < -1 then acc = -1 end
     end
     out[i + 1] = acc
+    if warm and i % 2048 == 2047 then warm.yield() end
   end
   local v1 = voices[1]
   local sampleFrames = v1.samples * frameRate / outRate
@@ -223,6 +225,7 @@ function Sample.renderCry(pcm, sampleRate, params, opts)
     gainL = (127 - pan) / 191
     gainR = (128 + pan) / 191
   end
+  local warm = package.loaded["src.core.game3.warm"]
   for i = 0, #out - 1 do
     local v = out[i + 1]
     if channels == 2 then
@@ -231,6 +234,7 @@ function Sample.renderCry(pcm, sampleRate, params, opts)
     else
       sd:setSample(i, v * (gainL + gainR) * 0.5)
     end
+    if warm and i % 2048 == 2047 then warm.yield() end
   end
   return sd, info
 end
diff --git a/src/core/game3/ow_sprites.lua b/src/core/game3/ow_sprites.lua
index 5cb15540..b081ee30 100644
--- a/src/core/game3/ow_sprites.lua
+++ b/src/core/game3/ow_sprites.lua
@@ -405,6 +405,15 @@ function OwSprites.getDraw(graphicsId)
   return OwSprites.get(graphicsId)
 end
 
+function OwSprites.peekDraw(graphicsId)
+  graphicsId = tonumber(graphicsId)
+  if graphicsId == nil then return nil end
+  local ov = OwSprites._overrides and OwSprites._overrides[graphicsId]
+  if ov or OwSprites._loaded[graphicsId] or not OwSprites._stream then return OwSprites.getDraw(graphicsId) end
+  OwSprites.prefetch(graphicsId, 0)
+  return nil
+end
+
 local function paletteRgb(colors)
   if type(colors) ~= "table" then return nil end
   local out = {}
diff --git a/src/core/game3/prewarm.lua b/src/core/game3/prewarm.lua
new file mode 100644
index 00000000..efc271f2
--- /dev/null
+++ b/src/core/game3/prewarm.lua
@@ -0,0 +1,96 @@
+local Warm = require("src.core.game3.warm")
+local Prewarm = {}
+
+Prewarm.FIELD_SE = { "SE_SELECT", "SE_WIN_OPEN", "SE_WALL_HIT", "SE_EXIT", "SE_RS_DOOR", "SE_LEDGE",
+  "SE_SLIDING_DOOR", "SE_PIN" }
+
+Prewarm.BATTLE_SE = { "SE_BALL_OPEN", "SE_BALL_THROW", "SE_FAINT", "SE_NOT_EFFECTIVE", "SE_EFFECTIVE",
+  "SE_SUPER_EFFECTIVE", "SE_EXP" }
+
+Prewarm.MODULES = {
+  "src.core.game3.party", "src.core.game3.trainer_sight", "src.core.game3.warp",
+  "src.core.game3.battle_downgrade", "src.core.game3.battle_bridge", "src.core.game3.battle_transition",
+  "src.core.game3.battle.ai", "src.core.game3.battle.ai_cmds", "src.core.game3.battle.ai_vm",
+  "src.core.game3.battle.ai_items", "src.core.game3.battle.link_guard", "src.ui.game3.stat_growth",
+  "src.ui.game3.map_name_popup",
+}
+
+Prewarm.FAMILY_MODULES = {
+  rse = { "src.core.game3.audio_policy_rse", "src.ui.game3.rse.mapsec", "src.ui.game3.rse.scene_kit",
+    "src.core.game3.battle_transition_ids_rse", "src.core.game3.battle_transition_rse_a",
+    "src.core.game3.battle_transition_rse_b", "src.core.game3.battle_transition_rse_frontier" },
+  frlg = { "src.core.game3.battle_transition_ids_frlg" },
+}
+
+Prewarm.FONT_FACES = { "normal", "small", "short", "narrow", "small_narrow" }
+
+Prewarm.CONSTANTS = { "weather", "region_map_sections", "trainer_classes", "moves", "abilities" }
+
+local function se_list(names, priority)
+  local Audio = package.loaded["src.core.game3.audio"]
+  if not Audio then return end
+  for _, name in ipairs(names) do Audio.prewarmSe(name, priority) end
+end
+
+function Prewarm.session(session)
+  local Profile = require("src.core.game3.profile")
+  local family = Profile.family(session)
+  Warm.require(Prewarm.MODULES, 6)
+  Warm.require(Prewarm.FAMILY_MODULES[family] or {}, 6)
+  local okG, game = pcall(function() return require("src.core.GameVersion").get() end)
+  if okG and game then
+    for _, kind in ipairs(Prewarm.CONSTANTS) do
+      Warm.add("const:" .. tostring(game) .. ":" .. kind, function()
+        local C = require("src.core.game3.constants").of(game)
+        local _ = C[kind]
+      end, 7)
+    end
+  end
+  for _, face in ipairs(Prewarm.FONT_FACES) do
+    Warm.add("font:" .. face, function()
+      local Font = require("src.ui.game3.frlg_font")
+      if Font.face then pcall(Font.face, { font = face }) end
+    end, 5)
+  end
+  Warm.add("data:pic_coords", function() require("src.core.game3.battle.pic_coords").active() end, 7)
+  Warm.add("data:mon_anim", function() require("src.core.game3.mon_anim_data").get() end, 7)
+  Warm.add("data:moves", function() require("src.core.game3.battle.moves").loadRomPack() end, 7)
+  se_list(Prewarm.FIELD_SE, 9)
+end
+
+local function species_of(mon)
+  if type(mon) ~= "table" then return nil end
+  return tonumber(mon.species or mon.speciesId)
+end
+
+local function lead_of(party)
+  for _, mon in ipairs(type(party) == "table" and party or {}) do
+    if type(mon) == "table" and not mon.isEgg and not mon.egg and (tonumber(mon.hp) or 1) > 0 then return mon end
+  end
+end
+
+function Prewarm.battle(session, foe)
+  local Audio = package.loaded["src.core.game3.audio"]
+  if not Audio then return end
+  local lead = lead_of(session and session.party)
+  local IntroSeq = package.loaded["src.core.game3.battle.intro_seq"]
+  local mode = lead and IntroSeq and IntroSeq.releaseCryMode and IntroSeq.releaseCryMode(lead) or 0
+  if species_of(lead) then Audio.prewarmCry(species_of(lead), mode, -25, 1) end
+  local first = foe and ((type(foe.party) == "table" and foe.party[1]) or foe)
+  if species_of(first) then Audio.prewarmCry(species_of(first), 0, 25, 1) end
+  se_list(Prewarm.BATTLE_SE, 2)
+end
+
+function Prewarm.battleStart(opts)
+  if type(opts) ~= "table" then return end
+  Warm.add("battle:chrome", function()
+    require("src.ui.game3.battle_chrome").ensureInstalled()
+    local BattleBg = require("src.core.game3.battle.bg")
+    require("src.ui.game3.battle_chrome").terrain(BattleBg.sheetKey(BattleBg.resolveOpts(opts)))
+  end, 1)
+  Warm.add("battle:back", function()
+    require("src.core.game3.trainer_pic").back(tonumber(opts.playerGender) or 0)
+  end, 1)
+end
+
+return Prewarm
diff --git a/src/core/game3/runtime.lua b/src/core/game3/runtime.lua
index 67fbec1c..61fd9471 100644
--- a/src/core/game3/runtime.lua
+++ b/src/core/game3/runtime.lua
@@ -466,7 +466,8 @@ function Runtime.install(mod)
   Runtime._mod = mod
   log("Runtime.install — display ownership + START intercept + game.ready")
 
-  local ok, World = pcall(lazyReq, "src.world.gen2.World")
+  local World = package.loaded["src.world.gen2.World"]
+  local ok = type(World) == "table"
   if ok and World and World.step and not World._game3RuntimeStep then
     local prev = World.step
     World.step = function(self, ...)
@@ -507,7 +508,8 @@ function Runtime.install(mod)
   end
 
   -- Own the frame: replace Gen2 drawScene presentation while active.
-  local ok2, Game2 = pcall(lazyReq, "src.core.Game2")
+  local Game2 = package.loaded["src.core.Game2"]
+  local ok2 = type(Game2) == "table"
   if ok2 and Game2 and Game2.drawScene and not Game2._game3Display then
     local prevDraw = Game2.drawScene
     Game2.drawScene = function(self, w, h)
diff --git a/src/core/game3/scripting/space.lua b/src/core/game3/scripting/space.lua
index 8098c81a..8c42d121 100644
--- a/src/core/game3/scripting/space.lua
+++ b/src/core/game3/scripting/space.lua
@@ -744,7 +744,8 @@ function Space.install(mod)
       end
     end
     -- Direct Gen2 World:setMap (ferry/warps often skip the facade).
-    local ok, World = pcall(lazyReq, "src.world.gen2.World")
+    local World = package.loaded["src.world.gen2.World"]
+    local ok = type(World) == "table"
     if ok and World and World.setMap and not World._game3SetMap then
       local prevW = World.setMap
       World.setMap = function(self, mapId, ...)
@@ -796,7 +797,8 @@ function Space.install(mod)
 
   -- Gen2 World:busy must see game3 scripts or frozeNpcs clears mid-dialog.
   do
-    local ok, World = pcall(lazyReq, "src.world.gen2.World")
+    local World = package.loaded["src.world.gen2.World"]
+    local ok = type(World) == "table"
     if ok and World and World.busy and not World._game3Busy then
       local prevBusy = World.busy
       World.busy = function(self)
diff --git a/src/core/game3/tileset_anim.lua b/src/core/game3/tileset_anim.lua
index 40004ece..d4f6940c 100644
--- a/src/core/game3/tileset_anim.lua
+++ b/src/core/game3/tileset_anim.lua
@@ -18,6 +18,12 @@ TilesetAnim._enabled = true
 
 local MID_RGBA = 16 * 16 * 4 -- 1024
 
+local nativeMod
+local function NativeTileset()
+  nativeMod = nativeMod or require("src.core.game3.tileset_native")
+  return nativeMod
+end
+
 local function log(msg)
   print("[game3/anim] " .. tostring(msg))
 end
@@ -167,6 +173,7 @@ local function rse_paste(entry, bank, blob, mids, quads, frame, imageData, lut,
       if piece then
         local ax, ay = (slot % cols) * 16, math.floor(slot / cols) * 16
         local mask = quads and quads[k] or 15
+        NativeTileset().markDirty(ts, over, slot)
         if mask == 15 then
           imageData:paste(piece, ax, ay, 0, 0, 16, 16)
         else
@@ -234,12 +241,6 @@ end
 
 local rseDirty = {}
 
-local nativeMod
-local function NativeTileset()
-  nativeMod = nativeMod or require("src.core.game3.tileset_native")
-  return nativeMod
-end
-
 -- pokeemerald/src/tileset_anims.c:586
 function TilesetAnim.stepRse()
   local st = TilesetAnim._rse
@@ -295,6 +296,49 @@ local function load_bank(cache, pair, kind, info)
   }
 end
 
+local get_frame_piece
+
+local function prewarm(pair, entry)
+  local Warm = require("src.core.game3.warm")
+  Warm.add("anim:" .. pair, function()
+    if TilesetAnim._pairs[pair] ~= entry then return end
+    NativeTileset().ensureAlt(entry.atlas)
+    if entry.rse then
+      for _, bank in ipairs(entry.banks) do
+        local row = bank and bank.row
+        if row and row.kind == "palette" then
+          if row.paletteSlot then NativeTileset().prepareSlot(entry.atlas, tonumber(row.paletteSlot) or 0) end
+        elseif row then
+          local frames = tonumber(row.frames) or 0
+          for frame = 0, frames - 1 do
+            local n, on = #(row.mids or EMPTY), #(row.overMids or EMPTY)
+            for k = 1, n do
+              if bank.under then rse_piece(entry, bank, bank.under, entry.lut, frame, k, n, false) end
+              if k % 4 == 0 then Warm.yield() end
+            end
+            for k = 1, on do
+              if bank.over then rse_piece(entry, bank, bank.over, entry.lutOver, frame, k, on, true) end
+              if k % 4 == 0 then Warm.yield() end
+            end
+            Warm.yield()
+          end
+        end
+      end
+    else
+      for _, bank in pairs(entry.banks) do
+        local nMids = #bank.mids
+        for frame = 0, bank.frames - 1 do
+          for mi = 1, nMids do
+            get_frame_piece(bank, frame, mi, (frame * nMids + (mi - 1)) * MID_RGBA)
+            if mi % 8 == 0 then Warm.yield() end
+          end
+          Warm.yield()
+        end
+      end
+    end
+  end, 3)
+end
+
 -- pokefirered/src/tileset_anims.c:223
 function TilesetAnim.bindPair(pair, atlas, prepared)
   if not Versions.NATIVE_RENDER or Versions.TILESET_ANIM == false then
@@ -314,6 +358,7 @@ function TilesetAnim.bindPair(pair, atlas, prepared)
       entry = rse_entry(cache, pair, atlas, man)
       TilesetAnim._pairs[pair] = entry
       if not entry then return false end
+      prewarm(pair, entry)
       if not TilesetAnim._rse then TilesetAnim.enterMap(pair, false) end
       TilesetAnim._visible[pair] = true
       return true
@@ -324,6 +369,7 @@ function TilesetAnim.bindPair(pair, atlas, prepared)
       flower = load_bank(cache, pair, "flower", man.flower),
     } }
     TilesetAnim._pairs[pair] = entry
+    prewarm(pair, entry)
   end
   TilesetAnim._visible[pair] = true
   if entry.rse then return true end
@@ -356,7 +402,7 @@ function TilesetAnim.setVisiblePairs(visible)
   end
 end
 
-local function get_frame_piece(bank, frame, mi, srcOff)
+function get_frame_piece(bank, frame, mi, srcOff)
   if not (love and love.image and love.image.newImageData) then return nil end
   local pieces = bank.pieces
   if not pieces then
@@ -395,6 +441,7 @@ function TilesetAnim._applyKind(entry, kind, frame, deferUpload)
       local ax = (slot % cols) * 16
       local ay = math.floor(slot / cols) * 16
       local piece = get_frame_piece(bank, frame, mi, srcOff)
+      NativeTileset().markDirty(ts, false, slot)
       local pasted = false
       if piece and ts.imageData.paste then
         ts.imageData:paste(piece, ax, ay)
diff --git a/src/core/game3/tileset_native.lua b/src/core/game3/tileset_native.lua
index 5e3a8beb..b0a38a52 100644
--- a/src/core/game3/tileset_native.lua
+++ b/src/core/game3/tileset_native.lua
@@ -166,11 +166,16 @@ local function scan_slot(blob, cols, slot, skipZero)
   local base = 13 + midCount * 2
   local lo, hi = slot * 16, slot * 16 + 15
   local n = 0
+  local cells = {}
+  out.cells = cells
+  local warm = package.loaded["src.core.game3.warm"]
   for i = 0, midCount * 256 - 1 do
     local b = blob:byte(base + i)
+    if warm and i % 16384 == 16383 then warm.yield() end
     if b and b >= lo and b <= hi and not (skipZero and b == 0) then
       local mid = math.floor(i / 256)
       local within = i % 256
+      cells[mid] = true
       n = n + 1
       out[n] = {
         (mid % cols) * 16 + within % 16,
@@ -200,43 +205,98 @@ local function retarget(old, new)
   end
 end
 
-local function flip(ts, imgKey, dataKey, altKey)
+local scratch
+local function cellData(data, x, y)
+  if not scratch then scratch = love.image.newImageData(16, 16) end
+  scratch:paste(data, 0, 0, x, y, 16, 16)
+  return scratch
+end
+
+local function merge(pend, slots, full)
+  if full or not slots then
+    pend.full, pend.slots = true, nil
+  elseif not pend.full then
+    pend.slots = pend.slots or {}
+    for slot in pairs(slots) do pend.slots[slot] = true end
+  end
+end
+
+local function apply(ts, image, data, pend)
+  if pend.full then
+    image:replacePixels(data)
+  elseif pend.slots then
+    local cols = ts.cols or 16
+    for slot in pairs(pend.slots) do
+      local x, y = (slot % cols) * 16, math.floor(slot / cols) * 16
+      image:replacePixels(cellData(data, x, y), 1, 1, x, y)
+    end
+  end
+  pend.full, pend.slots = false, nil
+end
+
+local function flip(ts, imgKey, dataKey, altKey, slots)
   local img, data = ts[imgKey], ts[dataKey]
   if not (img and data and img.replacePixels) then return end
+  ts._pend = ts._pend or setmetatable({}, { __mode = "k" })
+  local pend = ts._pend
   local alt = ts[altKey]
+  local full = not slots or not next(slots)
   if alt and alt.replacePixels then
-    alt:replacePixels(data)
+    pend[alt] = pend[alt] or {}
+    merge(pend[alt], slots, full)
+    apply(ts, alt, data, pend[alt])
   elseif love and love.graphics and love.graphics.newImage then
     alt = love.graphics.newImage(data)
     if alt.setFilter then alt:setFilter("nearest", "nearest") end
+    pend[alt] = {}
   else
     img:replacePixels(data)
     return
   end
+  pend[img] = pend[img] or {}
+  merge(pend[img], slots, full)
   ts[imgKey], ts[altKey] = alt, img
   retarget(img, alt)
 end
 
-function NativeTileset.flush(ts, under, over)
-  if under then flip(ts, "image", "imageData", "imageAlt") end
-  if over then flip(ts, "overImage", "overImageData", "overImageAlt") end
+function NativeTileset.markDirty(ts, over, slot)
+  local key = over and "_dirtyOver" or "_dirtyUnder"
+  local set = ts[key]
+  if not set then set = {}; ts[key] = set end
+  set[slot] = true
 end
 
-local function paint(imageData, list, colors)
+function NativeTileset.flush(ts, under, over)
+  local du, dov = ts._dirtyUnder, ts._dirtyOver
+  ts._dirtyUnder, ts._dirtyOver = nil, nil
+  if under then flip(ts, "image", "imageData", "imageAlt", du) end
+  if over then flip(ts, "overImage", "overImageData", "overImageAlt", dov) end
+end
+
+function NativeTileset.ensureAlt(ts)
+  for _, k in ipairs({ { "image", "imageData", "imageAlt" }, { "overImage", "overImageData", "overImageAlt" } }) do
+    local img, data = ts[k[1]], ts[k[2]]
+    if img and data and not ts[k[3]] and love and love.graphics and love.graphics.newImage then
+      local alt = love.graphics.newImage(data)
+      if alt.setFilter then alt:setFilter("nearest", "nearest") end
+      ts[k[3]] = alt
+    end
+  end
+end
+
+local function paint(ts, over, imageData, list, colors)
   if not (imageData and #list > 0) then return false end
   for i = 1, #list do
     local p = list[i]
     local c = colors[p[3]]
     imageData:setPixel(p[1], p[2], c[1] / 255, c[2] / 255, c[3] / 255, 1)
   end
+  for slot in pairs(list.cells or {}) do NativeTileset.markDirty(ts, over, slot) end
   return true
 end
 
 -- pokefirered/src/palette.c:88
-function NativeTileset.setSlotPalette(pairOrTs, slot, bgr16)
-  local ts = type(pairOrTs) == "table" and pairOrTs or NativeTileset.get(pairOrTs)
-  if not (ts and ts.imageData and type(bgr16) == "table") then return false end
-  slot = tonumber(slot) or 0
+function NativeTileset.prepareSlot(ts, slot)
   local pix = ts.slotPix[slot]
   if not pix then
     pix = {
@@ -245,10 +305,19 @@ function NativeTileset.setSlotPalette(pairOrTs, slot, bgr16)
     }
     ts.slotPix[slot] = pix
   end
+  return pix
+end
+
+function NativeTileset.setSlotPalette(pairOrTs, slot, bgr16)
+  local ts = type(pairOrTs) == "table" and pairOrTs or NativeTileset.get(pairOrTs)
+  if not (ts and ts.imageData and type(bgr16) == "table") then return false end
+  slot = tonumber(slot) or 0
+  local pix = NativeTileset.prepareSlot(ts, slot)
   local src = {}
   for c = 0, 15 do src[c] = bgr16[c + 1] or 0 end
   local colors = NativePack.palsToRgb8({ [0] = src })[0]
-  NativeTileset.flush(ts, paint(ts.imageData, pix.under, colors), paint(ts.overImageData, pix.over, colors))
+  NativeTileset.flush(ts, paint(ts, false, ts.imageData, pix.under, colors),
+    paint(ts, true, ts.overImageData, pix.over, colors))
   ts.patchedSlots = ts.patchedSlots or {}
   ts.patchedSlots[slot] = true
   return true
diff --git a/src/core/game3/warm.lua b/src/core/game3/warm.lua
new file mode 100644
index 00000000..71fe7c36
--- /dev/null
+++ b/src/core/game3/warm.lua
@@ -0,0 +1,83 @@
+local Warm = {}
+Warm.BUDGET = 0.002
+
+local jobs, order = {}, {}
+local clock = function() return love and love.timer and love.timer.getTime() or os.clock() end
+
+function Warm.add(key, fn, priority)
+  if jobs[key] then
+    if priority and priority < jobs[key].priority then jobs[key].priority = priority end
+    return false
+  end
+  local job = { key = key, fn = fn, priority = priority or 5 }
+  jobs[key] = job
+  order[#order + 1] = job
+  return true
+end
+
+function Warm.pending(key) return jobs[key] ~= nil end
+
+local function finish(job)
+  jobs[job.key] = nil
+  for i = #order, 1, -1 do
+    if order[i] == job then table.remove(order, i) break end
+  end
+end
+
+local function resume(job)
+  if not job.co then job.co = coroutine.create(job.fn) end
+  local ok, err = coroutine.resume(job.co)
+  if not ok then
+    print("[game3/warm] " .. tostring(job.key) .. ": " .. tostring(err))
+    finish(job)
+  elseif coroutine.status(job.co) == "dead" then
+    finish(job)
+  end
+end
+
+function Warm.flush(key)
+  local job = jobs[key]
+  if not job or (job.co and job.co == coroutine.running()) then return false end
+  job.flushing = true
+  while jobs[key] == job do resume(job) end
+  return true
+end
+
+function Warm.step(budget)
+  if #order == 0 then return end
+  local deadline = clock() + (budget or Warm.BUDGET)
+  repeat
+    local best
+    for _, job in ipairs(order) do
+      if not best or job.priority < best.priority then best = job end
+    end
+    if not best then return end
+    resume(best)
+  until clock() >= deadline
+end
+
+function Warm.require(names, priority)
+  for _, name in ipairs(names) do
+    if not package.loaded[name] then
+      Warm.add("mod:" .. name, function() pcall(require, name) end, priority or 8)
+    end
+  end
+end
+
+function Warm.yield()
+  local co, main = coroutine.running()
+  if co and not main then
+    for _, job in pairs(jobs) do
+      if job.co == co then
+        if not job.flushing then coroutine.yield() end
+        return
+      end
+    end
+  end
+end
+
+function Warm.reset()
+  jobs, order = {}, {}
+end
+
+return Warm
diff --git a/src/render/PaletteFX.lua b/src/render/PaletteFX.lua
index e49f7aa6..7354bddd 100644
--- a/src/render/PaletteFX.lua
+++ b/src/render/PaletteFX.lua
@@ -959,12 +959,13 @@ function PaletteFX.shadeMap()
 end
 
 local function invalidateColorCaches()
-  pcall(function() require("src.battle.BattleState").invalidate() end)
-  pcall(function() require("src.render.SpriteRenderer").invalidate() end)
+  local loaded = package.loaded
+  pcall(function() if loaded["src.battle.BattleState"] then loaded["src.battle.BattleState"].invalidate() end end)
+  pcall(function() if loaded["src.render.SpriteRenderer"] then loaded["src.render.SpriteRenderer"].invalidate() end end)
   pcall(function()
-    require("src.world.MapLoader").invalidateAll()
-    local Game = require("src.core.Game")
-    if Game.overworld and Game.overworld.map and Game.overworld.reloadMap then
+    if loaded["src.world.MapLoader"] then loaded["src.world.MapLoader"].invalidateAll() end
+    local Game = loaded["src.core.Game"]
+    if type(Game) == "table" and Game.overworld and Game.overworld.map and Game.overworld.reloadMap then
       Game.overworld:reloadMap(Game.overworld.map.id, "colors")
     end
   end)
@@ -995,8 +996,8 @@ function PaletteFX.setCustomRamp(ramp)
 end
 
 function PaletteFX.pickerActive()
-  local ok, Game = pcall(require, "src.core.Game")
-  local states = ok and Game.stack and Game.stack.states
+  local Game = package.loaded["src.core.Game"]
+  local states = type(Game) == "table" and Game.stack and Game.stack.states or nil
   local top = states and states[#states]
   return top ~= nil and top.screenId == "PaletteScreen"
 end
diff --git a/src/render/Renderer.lua b/src/render/Renderer.lua
index eeed022f..46890945 100644
--- a/src/render/Renderer.lua
+++ b/src/render/Renderer.lua
@@ -970,8 +970,8 @@ function Renderer:endFrame(zones, worldZones)
   local extendedBlackBand = false
   local bandR, bandG, bandB = 1, 1, 1
   if not self.worldActive then
-    local ok, Game = pcall(require, "src.core.Game")
-    local stack = ok and Game and Game.stack
+    local Game = package.loaded["src.core.Game"]
+    local stack = type(Game) == "table" and Game.stack
     local base = stack and stack.visibleBase and stack:visibleBase()
     local state = base and stack.states and stack.states[base]
     local ownState = self.surroundState
@@ -1214,8 +1214,8 @@ function Renderer:endFrame(zones, worldZones)
   -- field, so never cover it with the native back-sprite fallback.
   if self.extendedWorldBand and not self.worldOverride
      and not FaithfulRes.scaleCap() then
-    local ok, Game = pcall(require, "src.core.Game")
-    love.graphics.setColor(PaletteFX.paperShade(ok and Game and Game.data))
+    local Game = package.loaded["src.core.Game"]
+    love.graphics.setColor(PaletteFX.paperShade(type(Game) == "table" and Game.data or nil))
     love.graphics.rectangle("fill", uox, vuy, uvpw, vuh)
     love.graphics.setColor(1, 1, 1, 1)
   end
diff --git a/src/ui/game3/battle_chrome.lua b/src/ui/game3/battle_chrome.lua
index 9f2f42c6..6bfd854b 100644
--- a/src/ui/game3/battle_chrome.lua
+++ b/src/ui/game3/battle_chrome.lua
@@ -161,8 +161,18 @@ local TERRAIN_MT = {
   __index = function(_, key) return BattleChrome.terrain(key) end,
 }
 
+local function install_key(cache)
+  return tostring(cache) .. "|" .. battle_root()
+end
+
+function BattleChrome.ensureInstalled()
+  if BattleChrome._installKey == install_key(resolve_cache(nil)) and BattleChrome._manifest then return end
+  BattleChrome.install(nil)
+end
+
 function BattleChrome.install(cache)
   BattleChrome._cache = resolve_cache(cache)
+  BattleChrome._installKey = install_key(BattleChrome._cache)
   BattleChrome._manifest = nil
   BattleChrome._textbox = nil
   BattleChrome._playerBox = nil
diff --git a/src/ui/game3/rse/item_storage.lua b/src/ui/game3/rse/item_storage.lua
index 55e6d74f..e3e9beb5 100644
--- a/src/ui/game3/rse/item_storage.lua
+++ b/src/ui/game3/rse/item_storage.lua
@@ -19,6 +19,21 @@ local WIN = {
   yesno = Window.template(9, 7, 5, 4),
 }
 ItemStorage.WIN = WIN
+-- pokeruby/src/player_pc.c:973
+local WIN_RS = {
+  list = WIN.list,
+  message = WIN.message,
+  title = Window.template(1, 1, 10, 2),
+  -- pokeruby/src/player_pc.c:606
+  quantity = Window.template(7, 9, 6, 2),
+  -- pokeruby/src/player_pc.c:703
+  yesno = Window.template(8, 7, 5, 4),
+}
+ItemStorage.WIN_RS = WIN_RS
+
+local function is_rs()
+  return require("src.ui.game3.rs.player_pc_policy").matches(ItemStorage._session)
+end
 -- pokeemerald/src/player_pc.c:283
 local ITEM_X, UP_TEXT_Y = 8, 9
 -- pokeemerald/src/player_pc.c:699
@@ -53,10 +68,12 @@ local function pos()
 end
 
 local function narrow()
+  if is_rs() then return { font = "normal" } end
   return { font = "narrow" }
 end
 
 local function row_height()
+  if is_rs() then return 16 end
   local face = FrlgFont.face and FrlgFont.face(narrow())
   return face and face.height or 16
 end
@@ -384,7 +401,44 @@ local function frame(tpl)
   Window.fill(tpl, 1, 1, 1, 1)
 end
 
+-- pokeruby/src/player_pc.c:862
+local function draw_list_rs()
+  local tpl = WIN_RS.list
+  frame(tpl)
+  local ox = tpl.left * 8
+  local list = items()
+  local shown = page_items()
+  local font = narrow()
+  local ItemsData = require("src.core.game3.items_data")
+  for i = 0, shown - 1 do
+    local idx = ItemStorage.scroll + i
+    local y = (i * 2 + 2) * 8
+    local e = list[idx + 1]
+    if not e then
+      FrlgFont.draw(RomText.plain("gText_Cancel2"), ox, y,
+        { font = "normal", colors = { fg = FrlgFont.STDPAL[1], bg = { 0, 0, 0, 0 }, shadow = FrlgFont.STDPAL[8] } })
+      break
+    end
+    local colors = { fg = FrlgFont.STDPAL[ItemStorage.swapFrom == idx and 2 or 1], bg = { 0, 0, 0, 0 },
+      shadow = FrlgFont.STDPAL[8] }
+    FrlgFont.draw(item_name(e.id), ox, y, { font = "normal", colors = colors })
+    local pocket = ItemsData.pocketOf(e.id)
+    -- pokeruby/src/player_pc.c:815
+    if pocket ~= "KEY_ITEMS" and not ItemsData.isHm(e.id) then
+      local qx = 26 * 8
+      FrlgFont.draw("×", qx, y, { font = "normal", colors = colors })
+      local digits = tostring(tonumber(e.qty) or 0)
+      local dx = qx + FrlgFont.measure("×", font) + (3 - #digits) * 6
+      for c = 1, #digits do
+        FrlgFont.draw(digits:sub(c, c), dx + (c - 1) * 6, y, { font = "normal", colors = colors })
+      end
+    end
+  end
+  require("src.ui.game3.rs.menu_cursor").draw(ox, 16 + ItemStorage.row * 16, 13 * 8)
+end
+
 local function draw_list()
+  if is_rs() then return draw_list_rs() end
   local tpl = WIN.list
   frame(tpl)
   local ox, oy = tpl.left * 8, tpl.top * 8
@@ -427,14 +481,20 @@ end
 
 function ItemStorage.draw()
   if not ItemStorage.open then return end
-  local title = WIN.title
+  local rs = is_rs()
+  local W = rs and WIN_RS or WIN
+  local title = W.title
   frame(title)
   local t = RomText.plain(ItemStorage._toss and "gText_TossItem" or "gText_WithdrawItem")
-  -- pokeemerald/src/player_pc.c:960
-  Window.printPx(t, title.left * 8 + math.floor((104 - FrlgFont.measure(t)) / 2), title.top * 8 + 1)
+  if rs then
+    Window.printPx(t, title.left * 8, title.top * 8)
+  else
+    -- pokeemerald/src/player_pc.c:960
+    Window.printPx(t, title.left * 8 + math.floor((104 - FrlgFont.measure(t)) / 2), title.top * 8 + 1)
+  end
   draw_list()
-  draw_icon()
-  local m = WIN.message
+  if not rs then draw_icon() end
+  local m = W.message
   frame(m)
   local pitch = FrlgFont.linePitch()
   local y = m.top * 8 + 1
@@ -443,13 +503,13 @@ function ItemStorage.draw()
     y = y + pitch
   end
   if ItemStorage.state == "quantity" then
-    local q = WIN.quantity
+    local q = W.quantity
     frame(q)
     local s = RomText.plain("gText_xVar1", { stringVars = { string.format("%03d", ItemStorage.quantity) } })
     -- pokeemerald/src/player_pc.c:1361
     Window.printPx(s, q.left * 8 + math.floor((48 - FrlgFont.measure(s)) / 2), q.top * 8 + 1)
   elseif ItemStorage.state == "yesno" then
-    local yn = WIN.yesno
+    local yn = W.yesno
     frame(yn)
     local ph = Window.optionHeight()
     Window.printPx(RomText.plain("gText_Yes"), yn.left * 8 + 8, yn.top * 8 + 1)
diff --git a/tests/drivers/em_sendout_profile.lua b/tests/drivers/em_sendout_profile.lua
new file mode 100644
index 00000000..6f2e8383
--- /dev/null
+++ b/tests/drivers/em_sendout_profile.lua
@@ -0,0 +1,57 @@
+local U = require("tests.drivers.util")
+
+return function(game)
+  local fails = 0
+  local function result(ok, label)
+    print((ok and "PASS " or "FAIL ") .. label)
+    if not ok then fails = fails + 1 end
+  end
+  local function finish()
+    print(string.format("[driver] em_sendout_profile: %d failure(s)", fails))
+    love.event.quit(fails == 0 and 0 or 1)
+    U.wait(10)
+  end
+
+  for _ = 1, 900 do
+    if game.phase == "boot" and game.boot then break end
+    U.wait(1)
+  end
+  game:_handleBootAction({ action = "new_game", name = "NICK", gender = 0 })
+  U.wait(240)
+
+  local Runtime = require("src.core.game3.runtime")
+  local Party = require("src.core.game3.party")
+  local BattleBridge = require("src.core.game3.battle_bridge")
+  local Battle = require("src.core.game3.battle")
+  local Ui = require("src.core.game3.battle.ui")
+  local Map = require("src.core.game3.map")
+  local C = require("src.core.game3.constants").of("emerald")
+  local session = Runtime.getSession()
+  if not session then result(false, "field session"); return finish() end
+
+  local ok = pcall(function() Map.load(nil, game, "EM_ROUTE101", { x = 7, y = 13, facing = "down" }) end)
+  result(ok, "Route 101 loads")
+  U.wait(120)
+  session.party = {}
+  -- pokeemerald/src/battle_setup.c:923
+  Party.giveMon(session, C.species.byName.SPECIES_TREECKO, 5, "TREECKO")
+  print("SENDOUT_MARK battle_start")
+  local started = BattleBridge.startFirstBattle(Runtime._mod, game, { done = function() end })
+  result(started == true, "first battle started")
+  if not started then return finish() end
+
+  local lastTap, f = 0, 0
+  for _ = 1, 4000 do
+    if Battle.isActive() and Battle._phase == "command" and Ui._mode == "menu" then break end
+    f = f + 1
+    if Ui.dialogPending and Ui.dialogPending() and f - lastTap >= 14 then
+      lastTap = f
+      U.tap(game, "a")
+    else
+      U.wait(1)
+    end
+  end
+  result(Battle._phase == "command" and Ui._mode == "menu", "reached the action menu after send-out")
+  U.wait(30)
+  finish()
+end
diff --git a/tests/drivers/heap_census.lua b/tests/drivers/heap_census.lua
new file mode 100644
index 00000000..f2d7cd30
--- /dev/null
+++ b/tests/drivers/heap_census.lua
@@ -0,0 +1,74 @@
+local U = require("tests.drivers.util")
+
+local BIG = {}
+local function census()
+  collectgarbage("collect")
+  print(string.format("HEAP_AFTER_COLLECT_KB %.0f", collectgarbage("count")))
+  local seen, rows = {}, {}
+  local function size(t, depth)
+    if seen[t] then return 0, 0 end
+    seen[t] = true
+    local slots, bytes = 0, 0
+    for k, v in next, t do
+      slots = slots + 1
+      if type(v) == "string" then
+        bytes = bytes + #v
+        if #v > 262144 then BIG[#BIG + 1] = { #v, tostring(k) } end
+      end
+      if type(k) == "string" then bytes = bytes + #k end
+    end
+    return slots, bytes
+  end
+  local function walk(t, path, depth)
+    if type(t) ~= "table" or seen[t] or depth > 12 then return 0 end
+    local slots, bytes = size(t, depth)
+    local total = slots * 40 + bytes
+    for k, v in next, t do
+      if type(v) == "table" then
+        total = total + walk(v, path .. "." .. tostring(k), depth + 1)
+      elseif type(v) == "function" then
+        for i = 1, 60 do
+          local n, uv = debug.getupvalue(v, i)
+          if not n then break end
+          if type(uv) == "table" then total = total + walk(uv, path .. "." .. tostring(k) .. "^" .. n, depth + 1) end
+        end
+      end
+    end
+    rows[#rows + 1] = { path, total, slots }
+    return total
+  end
+  for name, mod in pairs(package.loaded) do
+    if type(mod) == "table" then walk(mod, name, 0) end
+    if type(mod) == "function" then
+      for i = 1, 60 do
+        local n, uv = debug.getupvalue(mod, i)
+        if not n then break end
+        if type(uv) == "table" then walk(uv, name .. "^" .. n, 1) end
+      end
+    end
+  end
+  walk(debug.getregistry(), "REG", 0)
+  table.sort(rows, function(a, b) return a[2] > b[2] end)
+  local bigTotal = 0
+  table.sort(BIG, function(a, b) return a[1] > b[1] end)
+  for i, b in ipairs(BIG) do bigTotal = bigTotal + b[1]; if i <= 25 then print(string.format("BIGSTR %8.0fKB key=%s", b[1] / 1024, b[2])) end end
+  print(string.format("BIGSTR_TOTAL %.0fKB n=%d", bigTotal / 1024, #BIG))
+  print(string.format("HEAP_TOTAL_KB %.0f", collectgarbage("count")))
+  local shown = 0
+  for _, r in ipairs(rows) do
+    if shown >= 60 then break end
+    print(string.format("HEAP %8.0fKB slots=%-8d %s", r[2] / 1024, r[3], r[1]))
+    shown = shown + 1
+  end
+end
+
+return function(game)
+  for _ = 1, 900 do
+    if game.phase == "boot" and game.boot then break end
+    U.wait(1)
+  end
+  game:_handleBootAction({ action = "new_game", name = "BRENDAN", gender = 0 })
+  U.wait(300)
+  census()
+  love.event.quit(0)
+end
diff --git a/tests/drivers/hitch_profile.lua b/tests/drivers/hitch_profile.lua
new file mode 100644
index 00000000..1f2c21c5
--- /dev/null
+++ b/tests/drivers/hitch_profile.lua
@@ -0,0 +1,100 @@
+local INNER = assert(os.getenv("HITCH_INNER"), "HITCH_INNER=tests/drivers/<driver>.lua")
+local LIMIT_MS = tonumber(os.getenv("HITCH_MS") or "8") or 8
+local DEPTH = tonumber(os.getenv("HITCH_DEPTH") or "10") or 10
+if os.getenv("HITCH_JIT") ~= "1" and jit then jit.off(); jit.flush() end
+
+local okProf, profile = pcall(require, "jit.profile")
+if os.getenv("HITCH_STACKS") == "0" then okProf = false end
+local frame, stacks, vm, samples = 0, {}, {}, 0
+local hitches, all, known = {}, {}, {}
+local frameStart, stuckShown
+local clock = love.timer.getTime
+
+local function top(map, n)
+  local rows = {}
+  for k, v in pairs(map) do rows[#rows + 1] = { k, v } end
+  table.sort(rows, function(a, b) return a[2] > b[2] end)
+  local out = {}
+  for i = 1, math.min(n, #rows) do out[i] = rows[i] end
+  return out
+end
+
+if okProf then
+  profile.start("i1", function(th, n, state)
+    samples = samples + n
+    vm[state] = (vm[state] or 0) + n
+    local s = profile.dumpstack(th, "pl < ", DEPTH)
+    stacks[s] = (stacks[s] or 0) + n
+    if frameStart and clock() - frameStart > 5 and not stuckShown then
+      stuckShown = true
+      print("HITCH_STUCK " .. profile.dumpstack(th, "pl\n", 40))
+    end
+  end)
+end
+
+local function reset() stacks, vm, samples = {}, {}, 0 end
+
+local baseUpdate, baseDraw = love.update, love.draw
+local tu, td, kb0
+love.update = function(dt)
+  frame = frame + 1
+  reset()
+  kb0 = collectgarbage("count")
+  local t = clock()
+  frameStart = t
+  baseUpdate(dt)
+  tu = (clock() - t) * 1000
+end
+love.draw = function()
+  local t = clock()
+  baseDraw()
+  td = (clock() - t) * 1000
+  local total = (tu or 0) + td
+  all[#all + 1] = total
+  if os.getenv("HITCH_STATUS") and frame % 60 == 0 then
+    local B = package.loaded["src.core.game3.battle"]
+    local T = package.loaded["src.core.game3.battle_transition"]
+    print(string.format("HITCH_STATUS frame=%d battle=%s phase=%s transition=%s",
+      frame, tostring(B and B.isActive and B.isActive()), tostring(B and B._phase),
+      tostring(T and T._transitionId)))
+  end
+  for name in pairs(package.loaded) do
+    if not known[name] then
+      known[name] = true
+      if frame > 1 then print(string.format("LAZY_REQUIRE frame=%d %s", frame, name)) end
+    end
+  end
+  if total >= LIMIT_MS then
+    local Map = package.loaded["src.core.game3.map"]
+    hitches[#hitches + 1] = total
+    print(string.format("HITCH frame=%d total=%.1fms update=%.1f draw=%.1f gcKB=%+.0f heapKB=%.0f map=%s samples=%d vm[N=%d I=%d C=%d G=%d J=%d]",
+      frame, total, tu or 0, td, collectgarbage("count") - (kb0 or 0), collectgarbage("count"),
+      tostring(Map and Map.current), samples, vm.N or 0, vm.I or 0, vm.C or 0, vm.G or 0, vm.J or 0))
+    for _, row in ipairs(top(stacks, 6)) do
+      print(string.format("  %3d  %s", row[2], row[1]))
+    end
+  end
+end
+
+local quit = love.event.quit
+love.event.quit = function(...)
+  table.sort(all)
+  local n = #all
+  local function p(q) return all[math.max(1, math.ceil(n * q))] or 0 end
+  print(string.format("HITCH_SUMMARY frames=%d hitches=%d p50=%.2f p95=%.2f p99=%.2f max=%.2f jit=%s",
+    n, #hitches, p(.5), p(.95), p(.99), all[n] or 0, tostring(jit and jit.status())))
+  local foreign = {}
+  for name in pairs(package.loaded) do
+    if name:find("^src%.[%w_]+%.gen2%.") or name:find("^src%.[%w_]+%.gen2$")
+        or name == "src.core.Game" or name == "src.core.Game2" or name == "src.world.OverworldController"
+        or name == "src.battle.BattleState" then
+      foreign[#foreign + 1] = name
+    end
+  end
+  table.sort(foreign)
+  print(string.format("FOREIGN_MODULES n=%d %s", #foreign, table.concat(foreign, " ")))
+  if okProf then profile.stop() end
+  return quit(...)
+end
+
+return assert(loadfile(INNER))()
diff --git a/tests/drivers/rs_bike_pc_items.lua b/tests/drivers/rs_bike_pc_items.lua
new file mode 100644
index 00000000..d97adc9c
--- /dev/null
+++ b/tests/drivers/rs_bike_pc_items.lua
@@ -0,0 +1,64 @@
+local U = require("tests.drivers.util")
+local DIR = os.getenv("POKEPORT_SHOT_DIR") or "/tmp/rs_bike_pc_items"
+
+local failures = 0
+local function check(ok, label)
+  print((ok and "PASS " or "FAIL ") .. label)
+  if not ok then failures = failures + 1 end
+  return ok
+end
+
+local function finish()
+  print((failures == 0 and "PASS" or "FAIL") .. " rs_bike_pc_items failures=" .. failures)
+  love.event.quit(failures == 0 and 0 or 1)
+  U.wait(10)
+end
+
+return function(game)
+  for _ = 1, 900 do
+    if game.phase == "boot" and game.boot then break end
+    U.wait(1)
+  end
+  game:_handleBootAction({ action = "new_game", name = "BRENDAN", gender = 0 })
+  U.wait(240)
+  local Runtime = require("src.core.game3.runtime")
+  local session = Runtime.getSession()
+  if not check(session ~= nil, "session") then return finish() end
+  local C = require("src.core.game3.constants").active(session)
+  local ItemUse = require("src.core.game3.item_use")
+  local Bag = require("src.core.game3.bag")
+
+  local bike = C:id("items", "ITEM_MACH_BIKE")
+  Bag.add(session.bag, bike, 1)
+  local ok, res, a, b, c = pcall(ItemUse.useField, session, session.bag, bike)
+  check(ok, "bike use indoors does not error (" .. tostring(ok and "" or res) .. ")")
+  check(ok and res == false and type(b) == "string" and b:find("DAD") ~= nil,
+    "bike indoors gives DAD's advice: " .. tostring(b))
+
+  local Storage = require("src.core.game3.storage")
+  local list = Storage.ensure(session).items
+  for i = #list, 1, -1 do list[i] = nil end
+  list[1] = { id = C:id("items", "ITEM_POTION"), qty = 5 }
+  list[2] = { id = C:id("items", "ITEM_SUPER_POTION"), qty = 12 }
+  list[3] = { id = C:id("items", "ITEM_HM01_CUT"), qty = 1 }
+  list[4] = { id = C:id("items", "ITEM_ACRO_BIKE"), qty = 1 }
+  local ItemStorage = require("src.ui.game3.rse.item_storage")
+  ItemStorage.show({ session = session })
+  U.wait(10)
+  check(U.still(game, DIR .. "/01_withdraw.png"), "withdraw shot")
+  U.tap(game, "down")
+  U.wait(6)
+  U.tap(game, "select")
+  U.wait(6)
+  check(U.still(game, DIR .. "/02_swap.png"), "swap shot")
+  U.tap(game, "b")
+  U.wait(6)
+  U.tap(game, "a")
+  U.wait(6)
+  check(U.still(game, DIR .. "/03_quantity.png"), "quantity shot")
+  U.tap(game, "b")
+  U.wait(4)
+  ItemStorage.close()
+  U.wait(4)
+  finish()
+end