diff --git a/engines/ags/engine/ac/game.cpp b/engines/ags/engine/ac/game.cpp
index 163efc2a06a..5fcbb48b17e 100644
--- a/engines/ags/engine/ac/game.cpp
+++ b/engines/ags/engine/ac/game.cpp
@@ -109,10 +109,6 @@ namespace AGS3 {
 using namespace AGS::Shared;
 using namespace AGS::Engine;
 
-#if AGS_PLATFORM_OS_IOS || AGS_PLATFORM_OS_ANDROID
-extern int _G(psp_gfx_renderer);
-#endif
-
 //=============================================================================
 // Audio
 //=============================================================================
diff --git a/engines/ags/engine/ac/global_game.cpp b/engines/ags/engine/ac/global_game.cpp
index 18604839074..93c34003082 100644
--- a/engines/ags/engine/ac/global_game.cpp
+++ b/engines/ags/engine/ac/global_game.cpp
@@ -77,10 +77,6 @@ using namespace AGS::Shared;
 
 extern int gui_disabled_style;
 
-#if AGS_PLATFORM_OS_IOS || AGS_PLATFORM_OS_ANDROID
-extern int _G(psp_gfx_renderer);
-#endif
-
 void GiveScore(int amnt) {
 	guis_need_update = 1;
 	_GP(play).score += amnt;
diff --git a/engines/ags/engine/gfx/gfx_util.cpp b/engines/ags/engine/gfx/gfx_util.cpp
index 298079fc2cf..c5b50c7a113 100644
--- a/engines/ags/engine/gfx/gfx_util.cpp
+++ b/engines/ags/engine/gfx/gfx_util.cpp
@@ -26,11 +26,6 @@
 
 namespace AGS3 {
 
-// CHECKME: is this hack still relevant?
-#if AGS_PLATFORM_OS_IOS || AGS_PLATFORM_OS_ANDROID
-extern int _G(psp_gfx_renderer);
-#endif
-
 namespace AGS {
 namespace Engine {
 
diff --git a/engines/ags/engine/platform/base/agsplatformdriver.cpp b/engines/ags/engine/platform/base/agsplatformdriver.cpp
index 97569bd0f40..e90ad0a82ce 100644
--- a/engines/ags/engine/platform/base/agsplatformdriver.cpp
+++ b/engines/ags/engine/platform/base/agsplatformdriver.cpp
@@ -190,10 +190,6 @@ void AGSPlatformDriver::PrintMessage(const Shared::DebugMessage &msg) {
 
 #if defined (AGS_HAS_CD_AUDIO)
 
-// from ac_cdplayer
-extern int _G(use_cdplayer);
-extern int _G(need_to_stop_cd);
-
 int numcddrives = 0;
 
 int cd_player_init() {
diff --git a/engines/ags/engine/platform/windows/gfx/ali3dd3d.cpp b/engines/ags/engine/platform/windows/gfx/ali3dd3d.cpp
index a53c0a328dd..0ce78f86634 100644
--- a/engines/ags/engine/platform/windows/gfx/ali3dd3d.cpp
+++ b/engines/ags/engine/platform/windows/gfx/ali3dd3d.cpp
@@ -49,9 +49,6 @@ namespace AGS3 {
 
 using namespace AGS::Shared;
 
-// Necessary to update textures from 8-bit bitmaps
-extern RGB palette[256];
-
 //
 // Following functions implement various matrix operations. Normally they are found in the auxiliary d3d9x.dll,
 // but we do not want AGS to be dependent on it.
diff --git a/engines/ags/engine/platform/windows/win_ex_handling.cpp b/engines/ags/engine/platform/windows/win_ex_handling.cpp
index c57f728ac33..f103d107f7c 100644
--- a/engines/ags/engine/platform/windows/win_ex_handling.cpp
+++ b/engines/ags/engine/platform/windows/win_ex_handling.cpp
@@ -41,9 +41,6 @@ namespace AGS3 {
 
 using namespace AGS::Shared;
 
-extern int _G(our_eip);
-extern int _G(eip_guinum);
-extern int _G(eip_guiobj);
 extern int proper_exit;
 
 char tempmsg[100];
diff --git a/engines/ags/engine/script/cc_instance.cpp b/engines/ags/engine/script/cc_instance.cpp
index 79bcf29e5e6..90375745ca2 100644
--- a/engines/ags/engine/script/cc_instance.cpp
+++ b/engines/ags/engine/script/cc_instance.cpp
@@ -50,14 +50,6 @@ namespace AGS3 {
 using namespace AGS::Shared;
 using namespace AGS::Shared::Memory;
 
-extern ccInstance *loadedInstances[MAX_LOADED_INSTANCES]; // in script/script_runtime
-
- // in script/script
-extern int maxWhileLoops;
-extern new_line_hook_type new_line_hook;
-
-
-
 enum ScriptOpArgIsReg {
 	kScOpNoArgIsReg     = 0,
 	kScOpArg1IsReg      = 0x0001,
@@ -356,8 +348,8 @@ int ccInstance::CallScriptFunction(const char *funcname, int32_t numargs, const
 	// object with ref count 0 that is in use
 	_GP(pool).RunGarbageCollectionIfAppropriate();
 
-	if (new_line_hook)
-		new_line_hook(nullptr, 0);
+	if (_G(new_line_hook))
+		_G(new_line_hook)(nullptr, 0);
 
 	if (reterr)
 		return -6;
@@ -525,8 +517,8 @@ int ccInstance::Run(int32_t curpc) {
 		case SCMD_LINENUM:
 			line_number = arg1.IValue;
 			_G(currentline) = arg1.IValue;
-			if (new_line_hook)
-				new_line_hook(this, _G(currentline));
+			if (_G(new_line_hook))
+				_G(new_line_hook)(this, _G(currentline));
 			break;
 		case SCMD_ADD:
 			// If the the register is SREG_SP, we are allocating new variable on the stack
@@ -760,13 +752,13 @@ int ccInstance::Run(int32_t curpc) {
 		case SCMD_JMP:
 			pc += arg1.IValue;
 
-			if ((arg1.IValue < 0) && (maxWhileLoops > 0) && (loopIterationCheckDisabled == 0)) {
+			if ((arg1.IValue < 0) && (_G(maxWhileLoops) > 0) && (loopIterationCheckDisabled == 0)) {
 				// Make sure it's not stuck in a While loop
 				loopIterations ++;
 				if (flags & INSTF_RUNNING) {
 					loopIterations = 0;
 					flags &= ~INSTF_RUNNING;
-				} else if (loopIterations > maxWhileLoops) {
+				} else if (loopIterations > _G(maxWhileLoops)) {
 					cc_error("!Script appears to be hung (a while loop ran %d times). The problem may be in a calling function; check the call stack.", loopIterations);
 					return -1;
 				}
@@ -943,7 +935,7 @@ int ccInstance::Run(int32_t curpc) {
 			// extract the instance ID
 			int32_t instId = codeOp.Instruction.InstanceId;
 			// determine the offset into the code of the instance we want
-			runningInst = loadedInstances[instId];
+			runningInst = _G(loadedInstances)[instId];
 			intptr_t callAddr = reg1.Ptr - (char *)&runningInst->code[0];
 			if (callAddr % sizeof(intptr_t) != 0) {
 				cc_error("call address not aligned");
@@ -1336,8 +1328,8 @@ bool ccInstance::_Create(PScript scri, ccInstance *joined) {
 
 	// find a LoadedInstance slot for it
 	for (i = 0; i < MAX_LOADED_INSTANCES; i++) {
-		if (loadedInstances[i] == nullptr) {
-			loadedInstances[i] = this;
+		if (_G(loadedInstances)[i] == nullptr) {
+			_G(loadedInstances)[i] = this;
 			loadedInstanceId = i;
 			break;
 		}
@@ -1413,8 +1405,8 @@ void ccInstance::Free() {
 	}
 
 	// remove from the Active Instances list
-	if (loadedInstances[loadedInstanceId] == this)
-		loadedInstances[loadedInstanceId] = nullptr;
+	if (_G(loadedInstances)[loadedInstanceId] == this)
+		_G(loadedInstances)[loadedInstanceId] = nullptr;
 
 	if ((flags & INSTF_SHAREDATA) == 0) {
 		nullfree(globaldata);
diff --git a/engines/ags/engine/script/script_runtime.cpp b/engines/ags/engine/script/script_runtime.cpp
index 4d6c62f4f63..26b2a28da83 100644
--- a/engines/ags/engine/script/script_runtime.cpp
+++ b/engines/ags/engine/script/script_runtime.cpp
@@ -83,11 +83,6 @@ void ccRemoveAllSymbols() {
 	_GP(simp).clear();
 }
 
-ccInstance *loadedInstances[MAX_LOADED_INSTANCES] = { nullptr,
-													 nullptr, nullptr, nullptr, nullptr, nullptr, nullptr, nullptr, nullptr, nullptr,
-													 nullptr, nullptr, nullptr, nullptr, nullptr, nullptr
-};
-
 void nullfree(void *data) {
 	if (data != nullptr)
 		free(data);
@@ -119,16 +114,11 @@ void *ccGetSymbolAddressForPlugin(const String &name) {
 	return nullptr;
 }
 
-new_line_hook_type new_line_hook = nullptr;
-
-char ccRunnerCopyright[] = "ScriptExecuter32 v" SCOM_VERSIONSTR " (c) 2001 Chris Jones";
-int maxWhileLoops = 0;
-
 // If a while loop does this many iterations without the
 // NofityScriptAlive function getting called, the script
 // aborts. Set to 0 to disable.
 void ccSetScriptAliveTimer(int numloop) {
-	maxWhileLoops = numloop;
+	_G(maxWhileLoops) = numloop;
 }
 
 void ccNotifyScriptStillAlive() {
@@ -137,7 +127,7 @@ void ccNotifyScriptStillAlive() {
 }
 
 void ccSetDebugHook(new_line_hook_type jibble) {
-	new_line_hook = jibble;
+	_G(new_line_hook) = jibble;
 }
 
 int call_function(intptr_t addr, const RuntimeScriptValue *object, int numparm, const RuntimeScriptValue *parms) {
diff --git a/engines/ags/globals.cpp b/engines/ags/globals.cpp
index 4d0d9d2c182..f19f6350c10 100644
--- a/engines/ags/globals.cpp
+++ b/engines/ags/globals.cpp
@@ -282,6 +282,10 @@ Globals::Globals() {
 	_objectScriptObjNames = new String[MAX_ROOM_OBJECTS];
 	_guiScriptObjNames = new std::vector<String>();
 
+	// script_runtime.cpp globals
+	Common::fill(_loadedInstances, _loadedInstances + MAX_LOADED_INSTANCES,
+		(ccInstance *)nullptr);
+
 	// systemimports.cpp globals
 	_simp = new SystemImports();
 	_simp_for_plugin = new SystemImports();
diff --git a/engines/ags/globals.h b/engines/ags/globals.h
index 075057d9dfc..1a01cae5d53 100644
--- a/engines/ags/globals.h
+++ b/engines/ags/globals.h
@@ -33,6 +33,7 @@
 #include "ags/engine/main/engine.h"
 #include "ags/engine/media/audio/audiodefines.h"
 #include "ags/engine/script/script.h"
+#include "ags/engine/script/script_runtime.h"
 #include "ags/lib/std/array.h"
 #include "ags/lib/std/set.h"
 #include "ags/lib/allegro/color.h"
@@ -1039,7 +1040,18 @@ public:
 	/**@}*/
 
 	/**
-	 * \defgroup script globals
+	 * \defgroup script_runtime globals
+	 * @{
+	 */
+
+	new_line_hook_type _new_line_hook = nullptr;
+	int _maxWhileLoops = 0;
+	ccInstance *_loadedInstances[MAX_LOADED_INSTANCES];
+
+	/**@}*/
+
+	/**
+	 * \defgroup systemimports globals
 	 * @{
 	 */