diff --git a/Aquaria/AquariaComboBox.cpp b/Aquaria/AquariaComboBox.cpp
index 803af98..4b5ba97 100644
--- a/Aquaria/AquariaComboBox.cpp
+++ b/Aquaria/AquariaComboBox.cpp
@@ -84,7 +84,7 @@ void AquariaComboBox::setScroll(size_t sc)
 
 std::string AquariaComboBox::getSelectedItemString()
 {
-	if (selectedItem >= 0 && selectedItem < items.size())
+	if (selectedItem < items.size())
 		return items[selectedItem];
 	return "";
 }
diff --git a/Aquaria/Continuity.cpp b/Aquaria/Continuity.cpp
index 1fef254..101ff74 100644
--- a/Aquaria/Continuity.cpp
+++ b/Aquaria/Continuity.cpp
@@ -495,7 +495,7 @@ void Continuity::setFishPoison(float m, float t)
 
 std::string Continuity::getIEString(IngredientData *data, size_t i)
 {
-	if (i < 0 || i >= data->effects.size()) return "";
+	if (i >= data->effects.size()) return "";
 
 	IngredientEffect fx = data->effects[i];
 	IngredientEffectType useType = fx.type;
@@ -2284,7 +2284,7 @@ void Continuity::loadPetData()
 
 PetData *Continuity::getPetData(size_t idx)
 {
-	if (idx < 0 || idx >= petData.size())
+	if (idx >= petData.size())
 	{
 		std::ostringstream os;
 		os << "getPetData(" << idx << ") index out of range";
diff --git a/Aquaria/DSQ.cpp b/Aquaria/DSQ.cpp
index e7543a7..5c495f3 100644
--- a/Aquaria/DSQ.cpp
+++ b/Aquaria/DSQ.cpp
@@ -2875,7 +2875,7 @@ void DSQ::prevSaveSlotPage()
 	if (saveSlots.empty()) return;
 
 	user.data.savePage--;
-	if (user.data.savePage < 0)
+	if (user.data.savePage > maxPages)
 		user.data.savePage = maxPages;
 	createSaveSlotPage();
 
diff --git a/Aquaria/SceneEditor.cpp b/Aquaria/SceneEditor.cpp
index e4d9e69..fc1ecbf 100644
--- a/Aquaria/SceneEditor.cpp
+++ b/Aquaria/SceneEditor.cpp
@@ -1468,7 +1468,7 @@ void SceneEditor::mouseButtonLeft()
 		{
 			Path *p = getSelectedPath();
 			editingPath = p;
-			if (p && selectedNode >= 0 && selectedNode < p->nodes.size())
+			if (p && selectedNode < p->nodes.size())
 			{
 				if (core->getShiftState())
 				{
@@ -2317,7 +2317,7 @@ void nextEntityPage()
 void prevEntityPage()
 {
 	game->sceneEditor.entityPageNum--;
-	if (game->sceneEditor.entityPageNum < 0)
+	if (game->sceneEditor.entityPageNum >= game->entityGroups.size())
 		game->sceneEditor.entityPageNum = game->entityGroups.size()-1;
 
 	createEntityPage();
@@ -2540,12 +2540,9 @@ void SceneEditor::doPrevElement()
 {
 	int oldCur = curElement;
 	curElement--;
-	if (curElement < 0)
+	if (curElement >= game->elementTemplates.size())
 		curElement = dsq->game->elementTemplates.size()-1;
 
-	if (curElement < 0)
-		return;
-
 	if (dsq->game->elementTemplates[curElement].idx < 1024)
 	{
 		placer->setTexture(dsq->game->elementTemplates[curElement].gfx);
@@ -3106,8 +3103,7 @@ void SceneEditor::update(float dt)
 			}
 			break;
 			case ES_MOVING:
-				if (selectedIdx >= 0)
-					dsq->game->getPath(selectedIdx)->nodes[selectedNode].position = dsq->getGameCursorPosition() + cursorOffset;
+				dsq->game->getPath(selectedIdx)->nodes[selectedNode].position = dsq->getGameCursorPosition() + cursorOffset;
 			break;
 			case ES_ROTATING:
 			case ES_MAX:
diff --git a/Aquaria/ScriptInterface.cpp b/Aquaria/ScriptInterface.cpp
index 3518fea..481d36f 100644
--- a/Aquaria/ScriptInterface.cpp
+++ b/Aquaria/ScriptInterface.cpp
@@ -8484,7 +8484,7 @@ luaFunc(setGemBlink)
 	size_t gemId = lua_tointeger(L, 1);
 	bool result = false;
 
-	if(gemId >= 0 && gemId < dsq->continuity.gems.size())
+	if(gemId < dsq->continuity.gems.size())
 	{
 		Continuity::Gems::iterator it = dsq->continuity.gems.begin();
 		std::advance(it, gemId);
@@ -8501,7 +8501,7 @@ luaFunc(setGemBlink)
 luaFunc(removeGem)
 {
 	size_t gemId = lua_tointeger(L, 1);
-	if(gemId >= 0 && gemId < dsq->continuity.gems.size())
+	if(gemId < dsq->continuity.gems.size())
 	{
 		Continuity::Gems::iterator it = dsq->continuity.gems.begin();
 		std::advance(it, gemId);
diff --git a/Aquaria/ScriptedEntity.cpp b/Aquaria/ScriptedEntity.cpp
index 4ae58be..a692a80 100644
--- a/Aquaria/ScriptedEntity.cpp
+++ b/Aquaria/ScriptedEntity.cpp
@@ -199,7 +199,7 @@ void ScriptedEntity::initSegments(int numSegments, int minDist, int maxDist, std
 	this->minDist = minDist;
 	this->maxDist = maxDist;
 	segments.resize(numSegments);
-	for (size_t i = segments.size()-1; i >= 0 ; i--)
+	for (size_t i = segments.size(); i-- >= 0 ; )
 	{
 		Quad *q = new Quad;
 		if (i == segments.size()-1)
diff --git a/BBGE/BitmapFont.cpp b/BBGE/BitmapFont.cpp
index 4323334..1e43482 100644
--- a/BBGE/BitmapFont.cpp
+++ b/BBGE/BitmapFont.cpp
@@ -281,12 +281,9 @@ void BitmapText::onUpdate(float dt)
 Vector BitmapText::getColorIndex(size_t i, size_t j)
 {
 	Vector c(1,1,1);
-	if (!(i < 0 || j < 0))
+	if ( i < colorIndices.size() && j < colorIndices[i].size())
 	{
-		if ( i < colorIndices.size() && j < colorIndices[i].size())
-		{
-			c = colorIndices[i][j];
-		}
+		c = colorIndices[i][j];
 	}
 	return c;
 }
diff --git a/BBGE/ParticleManager.cpp b/BBGE/ParticleManager.cpp
index b6e24ae..ac67281 100644
--- a/BBGE/ParticleManager.cpp
+++ b/BBGE/ParticleManager.cpp
@@ -207,14 +207,16 @@ void ParticleManager::nextFree(int jump)
 
 void ParticleManager::prevFree(int jump)
 {
-	free -= jump;
-	if (free < 0)
-		free += size;
+	if(free < jump) {
+		free = free + size - jump;
+	} else {
+		free -= jump;
+	}
 }
 
-void ParticleManager::setFree(int free)
+void ParticleManager::setFree(size_t free)
 {
-	if (free != -1)
+	if (free != ~0UL)
 	{
 		this->free = free;
 	}
diff --git a/BBGE/Particles.h b/BBGE/Particles.h
index 9f8b244..7ce9503 100644
--- a/BBGE/Particles.h
+++ b/BBGE/Particles.h
@@ -217,7 +217,7 @@ public:
 
 	void endParticle(Particle *p);
 
-	void setFree(int free);
+	void setFree(size_t free);
 
 	int getFree() { return free; }
 	int getNumActive() { return numActive; }
diff --git a/BBGE/Quad.cpp b/BBGE/Quad.cpp
index 87abfb7..2ae330f 100644
--- a/BBGE/Quad.cpp
+++ b/BBGE/Quad.cpp
@@ -106,7 +106,7 @@ void Quad::createGrid(int xd, int yd)
 
 void Quad::setDrawGridAlpha(size_t x, size_t y, float alpha)
 {
-	if (x < xDivs && x >= 0 && y < yDivs && y >= 0)
+	if (x < xDivs && y < yDivs)
 	{
 		drawGrid[x][y].z = alpha;
 	}
diff --git a/BBGE/SkeletalSprite.cpp b/BBGE/SkeletalSprite.cpp
index b292bd0..597605b 100644
--- a/BBGE/SkeletalSprite.cpp
+++ b/BBGE/SkeletalSprite.cpp
@@ -1093,7 +1093,7 @@ void SkeletalSprite::prevAnimation()
 {
 	stopAnimation();
 	animLayers[0].currentAnimation--;
-	if (animLayers[0].currentAnimation < 0)
+	if (animLayers[0].currentAnimation >= animations.size())
 		animLayers[0].currentAnimation = animations.size()-1;
 }
 
@@ -1878,7 +1878,7 @@ void SkeletalSprite::selectNextBone()
 		selectedBone--;
 		if(selectedBone == oldsel)
 			break;
-		if (selectedBone < 0)
+		if (selectedBone >= bones.size())
 			selectedBone = bones.size()-1;
 	}
 	while (!bones[selectedBone]->selectable);