diff --git a/src/game/camera.c b/src/game/camera.c
index 53814e8c..5420f643 100644
--- a/src/game/camera.c
+++ b/src/game/camera.c
@@ -678,7 +678,7 @@ f32 calc_y_to_curr_floor(f32 *posOff, f32 posMul, f32 posBound, f32 *focOff, f32
     }
 
     if (sMarioCamState->action & ACT_FLAG_ON_POLE) {
-        if (sMarioGeometry.currFloorHeight >= gMarioStates[0].usedObj->oPosY && sMarioCamState->pos[1]
+        if (gMarioStates[0].usedObj != NULL && sMarioGeometry.currFloorHeight >= gMarioStates[0].usedObj->oPosY && sMarioCamState->pos[1]
                    < 0.7f * gMarioStates[0].usedObj->hitboxHeight + gMarioStates[0].usedObj->oPosY) {
             posBound = 1200;
         }
@@ -2341,7 +2341,7 @@ s16 update_default_camera(struct Camera *c) {
         vec3f_copy(c->focus, sMarioCamState->pos);
     }
 
-    if (sMarioCamState->action & ACT_FLAG_ON_POLE) {
+    if ((sMarioCamState->action & ACT_FLAG_ON_POLE) && gMarioStates[0].usedObj != NULL) {
         camFloorHeight = gMarioStates[0].usedObj->oPosY + 125.f;
         if (sMarioCamState->pos[1] - 100.f > camFloorHeight) {
             camFloorHeight = sMarioCamState->pos[1] - 100.f;
diff --git a/src/game/interaction.c b/src/game/interaction.c
index 1cf16d3e..d5b23b09 100644
--- a/src/game/interaction.c
+++ b/src/game/interaction.c
@@ -299,7 +299,7 @@ void mario_stop_riding_object(struct MarioState *m) {
 
 void mario_grab_used_object(struct MarioState *m) {
     if (m->usedObj == NULL || m->usedObj->oHeldState == HELD_HELD) { return; }
-    if (m->heldObj == NULL) {
+    if (m->heldObj == NULL && m->usedObj != NULL) {
         m->heldObj = m->usedObj;
         m->heldObj->heldByPlayerIndex = m->playerIndex;
         obj_set_held_state(m->heldObj, bhvCarrySomething3);
@@ -349,7 +349,7 @@ void mario_stop_riding_and_holding(struct MarioState *m) {
     mario_drop_held_object(m);
     mario_stop_riding_object(m);
 
-    if (m->action == ACT_RIDING_HOOT) {
+    if (m->action == ACT_RIDING_HOOT && m->usedObj != NULL) {
         m->usedObj->oInteractStatus = 0;
         m->usedObj->oHootMarioReleaseTime = gGlobalTimer;
     }
@@ -421,7 +421,7 @@ struct Object *mario_get_collided_object(struct MarioState *m, u32 interactType)
     for (i = 0; i < m->marioObj->numCollidedObjs; i++) {
         object = m->marioObj->collidedObjs[i];
 
-        if (object->oInteractType == interactType) {
+        if (object != NULL && object->oInteractType == interactType) {
             return object;
         }
     }
@@ -574,6 +574,10 @@ static u32 unused_determine_knockback_action(struct MarioState *m) {
 }
 
 u32 determine_knockback_action(struct MarioState *m, UNUSED s32 arg) {
+    if (m->interactObj == NULL) {
+        return sForwardKnockbackActions[0][0];
+    }
+
     u32 bonkAction;
 
     s16 terrainIndex = 0; // 1 = air, 2 = water, 0 = default
@@ -707,6 +711,7 @@ u32 should_push_or_pull_door(struct MarioState *m, struct Object *o) {
 }
 
 u32 take_damage_from_interact_object(struct MarioState *m) {
+    if (m->interactObj == NULL) { return 0; }
     s32 shake;
     s32 damage = m->interactObj->oDamageOrCoinValue;
 
@@ -1688,7 +1693,7 @@ u32 interact_hoot(struct MarioState *m, UNUSED u32 interactType, struct Object *
 
     //! Can pause to advance the global timer without falling too far, allowing
     // you to regrab after letting go.
-    if (actionId >= 0x080 && actionId < 0x098
+    if (m->usedObj != NULL && actionId >= 0x080 && actionId < 0x098
         && (gGlobalTimer - m->usedObj->oHootMarioReleaseTime > 30)) {
         mario_stop_riding_and_holding(m);
         o->oInteractStatus = INT_STATUS_HOOT_GRABBED_BY_MARIO;
diff --git a/src/game/level_update.c b/src/game/level_update.c
index 497abef8..b30fa5eb 100644
--- a/src/game/level_update.c
+++ b/src/game/level_update.c
@@ -793,12 +793,14 @@ s16 level_trigger_warp(struct MarioState *m, s32 warpOp) {
                 break;
 
             case WARP_OP_UNKNOWN_02: // bbh enter
+                if (m->usedObj == NULL) { break; }
                 sDelayedWarpTimer = 30;
                 sSourceWarpNodeId = (m->usedObj->oBehParams & 0x00FF0000) >> 16;
                 play_transition(WARP_TRANSITION_FADE_INTO_COLOR, 0x1E, 0xFF, 0xFF, 0xFF);
                 break;
 
             case WARP_OP_TELEPORT:
+                if (m->usedObj == NULL) { break; }
                 sDelayedWarpTimer = 20;
                 sSourceWarpNodeId = (m->usedObj->oBehParams & 0x00FF0000) >> 16;
                 val04 = !music_changed_through_warp(sSourceWarpNodeId);
@@ -806,6 +808,7 @@ s16 level_trigger_warp(struct MarioState *m, s32 warpOp) {
                 break;
 
             case WARP_OP_WARP_DOOR:
+                if (m->usedObj == NULL) { break; }
                 sDelayedWarpTimer = 20;
                 sDelayedWarpArg = m->actionArg;
                 sSourceWarpNodeId = (m->usedObj->oBehParams & 0x00FF0000) >> 16;
@@ -814,6 +817,7 @@ s16 level_trigger_warp(struct MarioState *m, s32 warpOp) {
                 break;
 
             case WARP_OP_WARP_OBJECT:
+                if (m->usedObj == NULL) { break; }
                 sDelayedWarpTimer = 20;
                 sSourceWarpNodeId = (m->usedObj->oBehParams & 0x00FF0000) >> 16;
                 val04 = !music_changed_through_warp(sSourceWarpNodeId);
diff --git a/src/game/mario_actions_airborne.c b/src/game/mario_actions_airborne.c
index 0d16c34d..d8d64351 100644
--- a/src/game/mario_actions_airborne.c
+++ b/src/game/mario_actions_airborne.c
@@ -1928,12 +1928,12 @@ s32 act_flying(struct MarioState *m) {
 s32 act_riding_hoot(struct MarioState *m) {
     if (m->usedObj == NULL || m->usedObj->behavior != bhvHoot) {
         m->usedObj = cur_obj_nearest_object_with_behavior(bhvHoot);
-        for (int i = 0; i < MAX_PLAYERS; i++) {
-            if (m != &gMarioStates[i]) { continue; }
-            m->usedObj->heldByPlayerIndex = i;
-        }
+        if (m->usedObj == NULL) { return FALSE; }
+        m->usedObj->heldByPlayerIndex = m->playerIndex;
     }
 
+    if (m->usedObj == NULL) { return FALSE; }
+
     if (!(m->input & INPUT_A_DOWN) || (m->marioObj->oInteractStatus & INT_STATUS_MARIO_UNK7)) {
         m->usedObj->oInteractStatus = 0;
         m->usedObj->oHootMarioReleaseTime = gGlobalTimer;
diff --git a/src/game/mario_actions_automatic.c b/src/game/mario_actions_automatic.c
index 5e5f9256..7ec01064 100644
--- a/src/game/mario_actions_automatic.c
+++ b/src/game/mario_actions_automatic.c
@@ -32,7 +32,7 @@
 void add_tree_leaf_particles(struct MarioState *m) {
     f32 leafHeight;
 
-    if (m->usedObj->behavior == segmented_to_virtual(bhvTree)) {
+    if (m->usedObj != NULL && m->usedObj->behavior == segmented_to_virtual(bhvTree)) {
         // make leaf effect spawn higher on the Shifting Sand Land palm tree
         if (gCurrLevelNum == LEVEL_SSL) {
             leafHeight = 250.0f;
@@ -46,7 +46,7 @@ void add_tree_leaf_particles(struct MarioState *m) {
 }
 
 void play_climbing_sounds(struct MarioState *m, s32 b) {
-    s32 isOnTree = (m->usedObj->behavior == segmented_to_virtual(bhvTree));
+    s32 isOnTree = (m->usedObj != NULL && m->usedObj->behavior == segmented_to_virtual(bhvTree));
 
     if (b == 1) {
         if (is_anim_past_frame(m, 1)) {
@@ -61,6 +61,7 @@ void play_climbing_sounds(struct MarioState *m, s32 b) {
 
 s32 set_pole_position(struct MarioState *m, f32 offsetY) {
     if (m->usedObj == NULL) { m->usedObj = cur_obj_find_nearest_pole(); }
+    if (m->usedObj == NULL) { return POLE_NONE; }
 
     UNUSED s32 unused1;
     UNUSED s32 unused2;
@@ -121,6 +122,7 @@ s32 set_pole_position(struct MarioState *m, f32 offsetY) {
 s32 act_holding_pole(struct MarioState *m) {
     struct Object *marioObj = m->marioObj;
     if (m->usedObj == NULL) { m->usedObj = cur_obj_find_nearest_pole(); }
+    if (m->usedObj == NULL) { return FALSE; }
 
 #ifdef VERSION_JP
     if (m->input & INPUT_A_PRESSED) {
diff --git a/src/game/mario_actions_cutscene.c b/src/game/mario_actions_cutscene.c
index aff21d2d..b16d339a 100644
--- a/src/game/mario_actions_cutscene.c
+++ b/src/game/mario_actions_cutscene.c
@@ -377,7 +377,7 @@ s32 set_mario_npc_dialog(struct MarioState* m, s32 actionArg) {
     } else if (actionArg != 0 && mario_ready_to_speak(m)) {
         m->usedObj = gCurrentObject;
         set_mario_action(m, ACT_READING_NPC_DIALOG, actionArg);
-        if (m->playerIndex == 0) { localDialogNPCBehavior = (BehaviorScript*)m->usedObj->behavior; }
+        if (m->playerIndex == 0 && m->usedObj != NULL) { localDialogNPCBehavior = (BehaviorScript*)m->usedObj->behavior; }
         dialogState = 1; // starting dialog
     }
 
@@ -559,7 +559,7 @@ s32 act_reading_sign(struct MarioState *m) {
             m->pos[2] += marioObj->oMarioReadingSignDPosZ / 11.0f;
             // create the text box
             if (m->actionTimer++ == 10) {
-                if (m == &gMarioStates[0]) {
+                if (m == &gMarioStates[0] && m->usedObj != NULL) {
                     create_dialog_inverted_box(m->usedObj->oBehParams2ndByte);
                 }
                 m->actionState = 2;
@@ -831,10 +831,12 @@ s32 launch_mario_until_land(struct MarioState *m, s32 endAction, s32 animation,
 }
 
 s32 act_unlocking_key_door(struct MarioState *m) {
-    m->faceAngle[1] = m->usedObj->oMoveAngleYaw;
+    if (m->usedObj != NULL) {
+        m->faceAngle[1] = m->usedObj->oMoveAngleYaw;
 
-    m->pos[0] = m->usedObj->oPosX + coss(m->faceAngle[1]) * 75.0f;
-    m->pos[2] = m->usedObj->oPosZ + sins(m->faceAngle[1]) * 75.0f;
+        m->pos[0] = m->usedObj->oPosX + coss(m->faceAngle[1]) * 75.0f;
+        m->pos[2] = m->usedObj->oPosZ + sins(m->faceAngle[1]) * 75.0f;
+    }
 
     if (m->actionArg & 2) {
         m->faceAngle[1] += 0x8000;
@@ -858,7 +860,7 @@ s32 act_unlocking_key_door(struct MarioState *m) {
     stop_and_set_height_to_floor(m);
 
     if (is_anim_at_end(m)) {
-        if (m->usedObj->oBehParams >> 24 == 1) {
+        if (m->usedObj != NULL && ((m->usedObj->oBehParams >> 24) == 1)) {
             save_file_set_flags(SAVE_FLAG_UNLOCKED_UPSTAIRS_DOOR);
             save_file_clear_flags(SAVE_FLAG_HAVE_KEY_2);
         } else {
@@ -875,7 +877,9 @@ s32 act_unlocking_key_door(struct MarioState *m) {
 s32 act_unlocking_star_door(struct MarioState *m) {
     switch (m->actionState) {
         case 0:
-            m->faceAngle[1] = m->usedObj->oMoveAngleYaw;
+            if (m->usedObj != NULL) {
+                m->faceAngle[1] = m->usedObj->oMoveAngleYaw;
+            }
             if (m->actionArg & 2) {
                 m->faceAngle[1] += 0x8000;
             }
@@ -920,10 +924,12 @@ s32 act_entering_star_door(struct MarioState *m) {
     s16 targetAngle;
 
     if (m->actionTimer++ == 0) {
-        m->interactObj->oInteractStatus = 0x00010000;
+        if (m->interactObj != NULL) {
+            m->interactObj->oInteractStatus = 0x00010000;
+        }
 
         // ~30 degrees / 1/12 rot
-        targetAngle = m->usedObj->oMoveAngleYaw + 0x1555;
+        if (m->usedObj != NULL) { targetAngle = m->usedObj->oMoveAngleYaw + 0x1555; }
         if (m->actionArg & 2) {
             targetAngle += 0x5556; // ~120 degrees / 1/3 rot (total 150d / 5/12)
         }
@@ -931,8 +937,10 @@ s32 act_entering_star_door(struct MarioState *m) {
         // targetDX and targetDZ are the offsets to add to Mario's position to
         // have Mario stand 150 units in front of the door
 
-        targetDX = m->usedObj->oPosX + 150.0f * sins(targetAngle) - m->pos[0];
-        targetDZ = m->usedObj->oPosZ + 150.0f * coss(targetAngle) - m->pos[2];
+        if (m->usedObj != NULL) {
+            targetDX = m->usedObj->oPosX + 150.0f * sins(targetAngle) - m->pos[0];
+            targetDZ = m->usedObj->oPosZ + 150.0f * coss(targetAngle) - m->pos[2];
+        }
 
         m->marioObj->oMarioReadingSignDPosX = targetDX / 20.0f;
         m->marioObj->oMarioReadingSignDPosZ = targetDZ / 20.0f;
@@ -954,7 +962,9 @@ s32 act_entering_star_door(struct MarioState *m) {
     }
 
     else {
-        m->faceAngle[1] = m->usedObj->oMoveAngleYaw;
+        if (m->usedObj != NULL) {
+            m->faceAngle[1] = m->usedObj->oMoveAngleYaw;
+        }
 
         if (m->actionArg & 2) {
             m->faceAngle[1] += 0x8000;
@@ -978,10 +988,14 @@ s32 act_entering_star_door(struct MarioState *m) {
 s32 act_going_through_door(struct MarioState *m) {
     if (m->actionTimer == 0) {
         if (m->actionArg & 1) {
-            m->interactObj->oInteractStatus = 0x00010000;
+            if (m->interactObj != NULL) {
+                m->interactObj->oInteractStatus = 0x00010000;
+            }
             set_mario_animation(m, MARIO_ANIM_PULL_DOOR_WALK_IN);
         } else {
-            m->interactObj->oInteractStatus = 0x00020000;
+            if (m->interactObj != NULL) {
+                m->interactObj->oInteractStatus = 0x00020000;
+            }
             set_mario_animation(m, MARIO_ANIM_PUSH_DOOR_WALK_IN);
         }
     }