diff --git a/src/game/cheats.c b/src/game/cheats.c
index 8476d4a49..52128669d 100644
--- a/src/game/cheats.c
+++ b/src/game/cheats.c
@@ -75,7 +75,7 @@ void cheatActivate(s32 cheat_id)
 		break;
 	case CHEAT_ALLGUNS:
 		// Give all guns if only one player playing
-		if (PLAYERCOUNT() == 1 && g_Vars.unk000318 == 0) {
+		if (PLAYERCOUNT() == 1 && g_Vars.mplayerisrunning == false) {
 			prevplayernum = g_Vars.currentplayernum;
 
 			for (playernum = 0; playernum < PLAYERCOUNT(); playernum++) {
@@ -112,7 +112,7 @@ void cheatDeactivate(s32 cheat_id)
 		setCurrentPlayerNum(prevplayernum);
 		break;
 	case CHEAT_ALLGUNS:
-		if (PLAYERCOUNT() == 1 && g_Vars.unk000318 == 0) {
+		if (PLAYERCOUNT() == 1 && g_Vars.mplayerisrunning == false) {
 			prevplayernum = g_Vars.currentplayernum;
 
 			for (playernum = 0; playernum < PLAYERCOUNT(); playernum++) {
@@ -148,8 +148,8 @@ void cheatsActivate(void)
 		g_CheatsActiveBank0 = g_CheatsEnabledBank0;
 		g_CheatsActiveBank1 = g_CheatsEnabledBank1;
 
-		if (g_Vars.coopplayernum >= 0 || g_Vars.antiplayernum >= 0 || g_Vars.unk000318) {
-			// Co-op/counter-op - deactivate "Weapons for Jo in Solo" cheats
+		if (g_Vars.coopplayernum >= 0 || g_Vars.antiplayernum >= 0 || g_Vars.mplayerisrunning) {
+			// Co-op/counter-op/multi - deactivate "Weapons for Jo in Solo" cheats
 			g_CheatsActiveBank0 &= ~(
 				(1 << CHEAT_TRENTSMAGNUM) |
 				(1 << CHEAT_FARSIGHT) |
diff --git a/src/game/chr/chr.c b/src/game/chr/chr.c
index 7fe715767..1b85fc3c6 100644
--- a/src/game/chr/chr.c
+++ b/src/game/chr/chr.c
@@ -50002,13 +50002,15 @@ bool chrCompareTeams(struct chrdata *chr1, struct chrdata *chr2, u8 checktype)
 		}
 
 		if (checktype == 1) { // Return true if chrs are friends
-			if (g_Vars.unk000318) {
+			if (g_Vars.mplayerisrunning) {
 				if ((g_MpSetup.options & MPOPTION_TEAMSENABLED) && chr2->team == chr1->team) {
 					return true;
 				}
 			} else {
 				if (g_Vars.bond && g_Vars.bond->prop) {
 					struct chrdata *playerchr = g_Vars.bond->prop->chr;
+
+					// @bug: This makes Jon an ally in Duel
 					if ((chr2 == playerchr && chr1->headnum == HEAD_JONATHAN) ||
 							(chr1 == playerchr && chr2->headnum == HEAD_JONATHAN)) {
 						return true;
@@ -50020,13 +50022,15 @@ bool chrCompareTeams(struct chrdata *chr1, struct chrdata *chr2, u8 checktype)
 				}
 			}
 		} else if (checktype == 2) { // Return true if chrs are enemies
-			if (g_Vars.unk000318) {
+			if (g_Vars.mplayerisrunning) {
 				if ((g_MpSetup.options & MPOPTION_TEAMSENABLED) == 0 || chr2->team != chr1->team) {
 					return true;
 				}
 			} else {
 				if (g_Vars.bond && g_Vars.bond->prop) {
 					struct chrdata *playerchr = g_Vars.bond->prop->chr;
+
+					// @bug: This makes Jon an ally in Duel
 					if ((chr2 == playerchr && chr1->headnum == HEAD_JONATHAN) ||
 							(chr1 == playerchr && chr2->headnum == HEAD_JONATHAN)) {
 						return false;
diff --git a/src/game/chr/chraicommands.c b/src/game/chr/chraicommands.c
index 3cd4d6c04..b8b6a5bb7 100644
--- a/src/game/chr/chraicommands.c
+++ b/src/game/chr/chraicommands.c
@@ -14184,7 +14184,7 @@ glabel ai01dd
  */
 bool aiIfCoopMode(void)
 {
-	if (g_Vars.unk000318 == 0 && g_MissionConfig.iscoop) {
+	if (g_Vars.mplayerisrunning == false && g_MissionConfig.iscoop) {
 		u8 *cmd = g_Vars.ailist + g_Vars.aioffset;
 		g_Vars.aioffset = chraiGoToLabel(g_Vars.ailist, g_Vars.aioffset, cmd[2]);
 	} else {
diff --git a/src/game/game_0f09f0.c b/src/game/game_0f09f0.c
index 092f8c73f..aa976197c 100644
--- a/src/game/game_0f09f0.c
+++ b/src/game/game_0f09f0.c
@@ -16333,7 +16333,7 @@ void activemenuChangeScreen(s32 step)
 
 	g_ActiveMenuThings[g_ActiveMenuIndex].screenindex += step;
 
-	if (g_Vars.unk000318 && (g_MpSetup.options & MPOPTION_TEAMSENABLED)) {
+	if (g_Vars.mplayerisrunning && (g_MpSetup.options & MPOPTION_TEAMSENABLED)) {
 		if (g_ActiveMenuThings[g_ActiveMenuIndex].unk32) {
 			// Weapon selection, second function, and ...?
 			maxscreenindex = 2;
diff --git a/src/game/game_176d70.c b/src/game/game_176d70.c
index 7854717a4..e93e81b53 100644
--- a/src/game/game_176d70.c
+++ b/src/game/game_176d70.c
@@ -14670,7 +14670,7 @@ glabel func0f185568
 
 void scenarioCallback10(void)
 {
-	if (g_Vars.unk000318 != 0) {
+	if (g_Vars.mplayerisrunning) {
 		if (g_Vars.lvframenum == 5) {
 			func0f185568();
 		}
@@ -14683,7 +14683,7 @@ void scenarioCallback10(void)
 
 void scenarioCallback14(struct chrdata *chr)
 {
-	if (g_Vars.unk000318 && g_MpScenarios[g_MpSetup.scenario].unk14) {
+	if (g_Vars.mplayerisrunning && g_MpScenarios[g_MpSetup.scenario].unk14) {
 		g_MpScenarios[g_MpSetup.scenario].unk14(chr);
 	}
 }
@@ -15097,7 +15097,7 @@ glabel func0f185c14
 
 s32 scenarioRadar(s32 value)
 {
-	if (g_Vars.unk000318 && g_MpScenarios[g_MpSetup.scenario].radarfunc) {
+	if (g_Vars.mplayerisrunning && g_MpScenarios[g_MpSetup.scenario].radarfunc) {
 		return g_MpScenarios[g_MpSetup.scenario].radarfunc(value);
 	}
 
@@ -15106,7 +15106,7 @@ s32 scenarioRadar(s32 value)
 
 bool scenarioRadar2(s32 *displaylist, struct prop *prop)
 {
-	if (g_Vars.unk000318 && g_MpScenarios[g_MpSetup.scenario].radar2func) {
+	if (g_Vars.mplayerisrunning && g_MpScenarios[g_MpSetup.scenario].radar2func) {
 		return g_MpScenarios[g_MpSetup.scenario].radar2func(displaylist, prop);
 	}
 
@@ -15350,7 +15350,7 @@ f32 scenarioCallback2c(f32 arg0, s32 arg1, s32 arg2, struct prop *prop)
 {
 	f32 result;
 
-	if (g_Vars.unk000318 && g_MpScenarios[g_MpSetup.scenario].unk2c &&
+	if (g_Vars.mplayerisrunning && g_MpScenarios[g_MpSetup.scenario].unk2c &&
 			g_MpScenarios[g_MpSetup.scenario].unk2c(arg0, arg1, arg2, prop, &result)) {
 		return result;
 	}
diff --git a/src/include/gvars/gvars.h b/src/include/gvars/gvars.h
index 454438c81..cf31c560b 100644
--- a/src/include/gvars/gvars.h
+++ b/src/include/gvars/gvars.h
@@ -79,7 +79,7 @@ struct g_vars {
 	/*00030c*/ u32 unk00030c;
 	/*000310*/ u32 unk000310;
 	/*000314*/ u32 unk000314;
-	/*000318*/ u32 unk000318;
+	/*000318*/ bool mplayerisrunning;
 	/*00031c*/ u32 unk00031c;
 	/*000320*/ u32 unk000320;
 	/*000324*/ u32 unk000324;