diff --git a/Boxer/Application Delegate/BXAppController+BXGamesFolder.m b/Boxer/Application Delegate/BXAppController+BXGamesFolder.m
index c551e97f..71badba3 100644
--- a/Boxer/Application Delegate/BXAppController+BXGamesFolder.m	
+++ b/Boxer/Application Delegate/BXAppController+BXGamesFolder.m	
@@ -142,7 +142,6 @@ - (NSURL *) shelfArtworkURL
 {
     BOOL useRetinaAssets = NO;
     //10.7 and up
-    if ([[NSScreen mainScreen] respondsToSelector: @selector(convertRectToBacking:)])
     {
         NSRect backingPixel = [[NSScreen mainScreen] convertRectToBacking: NSMakeRect(0, 0, 1, 1)];
         useRetinaAssets = (backingPixel.size.width >= 2.0);
diff --git a/Boxer/BXImportWindowController.m b/Boxer/BXImportWindowController.m
index 01852424..2dd384ee 100644
--- a/Boxer/BXImportWindowController.m
+++ b/Boxer/BXImportWindowController.m
@@ -25,8 +25,7 @@ - (void) windowDidLoad
 	self.currentPanel = self.dropzonePanel;
     
     //Disable window restoration.
-    if ([self.window respondsToSelector: @selector(setRestorable:)])
-        self.window.restorable = NO;
+	self.window.restorable = NO;
 
     //Observe ourselves for changes to the document or its import stage,
     //so we can sync the active panel.
@@ -148,7 +147,6 @@ - (void) handOffToController: (NSWindowController *)controller
     
     //Suppress the default Lion window animations...
     NSWindowAnimationBehavior oldToBehavior = NSWindowAnimationBehaviorDefault, oldFromBehavior = NSWindowAnimationBehaviorDefault;
-    if ([toWindow respondsToSelector: @selector(setAnimationBehavior:)])
     {
         oldToBehavior = toWindow.animationBehavior;
         oldFromBehavior = fromWindow.animationBehavior;
@@ -165,7 +163,6 @@ - (void) handOffToController: (NSWindowController *)controller
     [fromWindow orderOut: self];
     
     //...and then turn the Lion animations back on after the transition is complete.
-    if ([toWindow respondsToSelector: @selector(setAnimationBehavior:)])
     {
         toWindow.animationBehavior = oldToBehavior;
         fromWindow.animationBehavior = oldFromBehavior;
@@ -195,7 +192,6 @@ - (void) pickUpFromController: (NSWindowController *)controller
     
     //Suppress the default Lion window animations...
     NSWindowAnimationBehavior oldToBehavior = NSWindowAnimationBehaviorDefault, oldFromBehavior = NSWindowAnimationBehaviorDefault;
-    if ([toWindow respondsToSelector: @selector(setAnimationBehavior:)])
     {
         oldToBehavior = toWindow.animationBehavior;
         oldFromBehavior = fromWindow.animationBehavior;
@@ -215,7 +211,6 @@ - (void) pickUpFromController: (NSWindowController *)controller
     [fromWindow orderOut: self];
     
     //...and then turn them back on after the transition is complete.
-    if ([toWindow respondsToSelector: @selector(setAnimationBehavior:)])
     {
         toWindow.animationBehavior = oldToBehavior;
         fromWindow.animationBehavior = oldFromBehavior;
diff --git a/Boxer/BXScroller.m b/Boxer/BXScroller.m
index 4c307292..72eb57df 100644
--- a/Boxer/BXScroller.m
+++ b/Boxer/BXScroller.m
@@ -29,7 +29,7 @@ - (BOOL) isVertical
 
 - (NSSize) knobMargin
 {
-    if ([self respondsToSelector: @selector(scrollerStyle)] && [self scrollerStyle] == NSScrollerStyleOverlay)
+    if ([self scrollerStyle] == NSScrollerStyleOverlay)
     {
         return NSMakeSize(2.0f, 3.0f);
     }
@@ -41,7 +41,7 @@ - (NSSize) knobMargin
 
 - (NSSize) slotMargin
 {
-    if ([self respondsToSelector: @selector(scrollerStyle)] && [self scrollerStyle] == NSScrollerStyleOverlay)
+    if ([self scrollerStyle] == NSScrollerStyleOverlay)
     {
         return NSMakeSize(1.0f, 2.0f);
     }
@@ -88,17 +88,7 @@ - (BOOL) isOpaque { return NO; }
 - (void) drawRect: (NSRect)dirtyRect
 {
     //On 10.7 and above, the regular NSScroller class should handle drawing
-    if ([self respondsToSelector: @selector(scrollerStyle)])
-    {
-        [super drawRect: dirtyRect];
-    }
-    //On 10.6 and below, we wish to override drawing to avoid drawing the 'caps'
-    //on the end of the standard scroller.
-    else
-    {
-        [self drawKnobSlotInRect: [self rectForPart: NSScrollerKnobSlot] highlight: NO];
-        [self drawKnob];
-    }
+    [super drawRect: dirtyRect];
 }
 
 - (void) drawKnob
@@ -186,7 +176,7 @@ @implementation BXHUDScroller
 
 - (NSSize) knobMargin
 {
-    if ([self respondsToSelector: @selector(scrollerStyle)] && [self scrollerStyle] == NSScrollerStyleOverlay)
+    if ([self scrollerStyle] == NSScrollerStyleOverlay)
     {
         return NSMakeSize(2.0f, 2.0f);
     }
@@ -198,7 +188,7 @@ - (NSSize) knobMargin
 
 - (NSSize) slotMargin
 {
-    if ([self respondsToSelector: @selector(scrollerStyle)] && [self scrollerStyle] == NSScrollerStyleOverlay)
+    if ([self scrollerStyle] == NSScrollerStyleOverlay)
     {
         return NSMakeSize(1.0f, 1.0f);
     }
diff --git a/Boxer/BXShelfArt.m b/Boxer/BXShelfArt.m
index e5188093..24322d1f 100644
--- a/Boxer/BXShelfArt.m
+++ b/Boxer/BXShelfArt.m
@@ -64,7 +64,6 @@ - (NSImage *) tiledImageWithPixelSize: (NSSize)pixelSize
     NSSize logicalSize = pixelSize;
     
     //TODO: ask our drawing context to do the conversion itself
-    if ([[NSScreen mainScreen] respondsToSelector: @selector(convertRectFromBacking:)])
     {
         NSRect pixelFrame = NSMakeRect(0, 0, pixelSize.width, pixelSize.height);
         logicalSize = [[NSScreen mainScreen] convertRectFromBacking: pixelFrame].size;
diff --git a/Boxer/DOS window/BXDOSWindowController.m b/Boxer/DOS window/BXDOSWindowController.m
index 72ed2943..8579ac0a 100644
--- a/Boxer/DOS window/BXDOSWindowController.m	
+++ b/Boxer/DOS window/BXDOSWindowController.m	
@@ -171,8 +171,7 @@ - (void) windowDidLoad
 	self.window.acceptsMouseMovedEvents = YES;
 	
     //Disable window restoration.
-    if ([self.window respondsToSelector: @selector(setRestorable:)])
-        self.window.restorable = NO;
+    self.window.restorable = NO;
     
     //Adjust the window's initial dimensions to suit the current aspect-ratio correction settings.
     BOOL aspectCorrectText = [[NSUserDefaults standardUserDefaults] boolForKey: @"aspectCorrectedText"];
diff --git a/Boxer/DOS window/BXLaunchPanelController.m b/Boxer/DOS window/BXLaunchPanelController.m
index ff6bae59..17d94401 100644
--- a/Boxer/DOS window/BXLaunchPanelController.m	
+++ b/Boxer/DOS window/BXLaunchPanelController.m	
@@ -62,14 +62,11 @@ - (void) viewDidLoad {
     [super viewDidLoad];
     
     //These attributes are unsupported in 10.6 and so cannot be defined in the XIB.
-    if ([self.launcherScrollView respondsToSelector: @selector(setScrollerKnobStyle:)])
-        self.launcherScrollView.scrollerKnobStyle = NSScrollerKnobStyleLight;
+    self.launcherScrollView.scrollerKnobStyle = NSScrollerKnobStyleLight;
     
-    if ([self.launcherScrollView respondsToSelector: @selector(setUsesPredominantAxisScrolling:)])
-        self.launcherScrollView.usesPredominantAxisScrolling = YES;
+    self.launcherScrollView.usesPredominantAxisScrolling = YES;
     
-    if ([self.launcherScrollView respondsToSelector: @selector(setHorizontalScrollElasticity:)])
-        self.launcherScrollView.horizontalScrollElasticity = NSScrollElasticityNone;
+    self.launcherScrollView.horizontalScrollElasticity = NSScrollElasticityNone;
 }
 
 - (void) setRepresentedObject: (id)representedObject
diff --git a/Boxer/DOS window/BXProgramPanelController.m b/Boxer/DOS window/BXProgramPanelController.m
index dd23301b..03c4c56e 100644
--- a/Boxer/DOS window/BXProgramPanelController.m	
+++ b/Boxer/DOS window/BXProgramPanelController.m	
@@ -110,10 +110,7 @@ - (void) awakeFromNib
 {
     //Disable vertical scrolling on 10.7: while we can only scroll horizontally, it's still otherwise
     //possible for the user to pull on the content vertically, and this causes ugly redraw errors.
-    if ([[self programScroller] respondsToSelector: @selector(setVerticalScrollElasticity:)])
-    {
-        [[self programScroller] setVerticalScrollElasticity: NSScrollElasticityNone];
-    }
+    [[self programScroller] setVerticalScrollElasticity: NSScrollElasticityNone];
 }
 
 - (void) syncActivePanel
diff --git a/Boxer/Documentation Panel/BXDocumentationBrowser.m b/Boxer/Documentation Panel/BXDocumentationBrowser.m
index 9ef5d912..e0369bda 100644
--- a/Boxer/Documentation Panel/BXDocumentationBrowser.m	
+++ b/Boxer/Documentation Panel/BXDocumentationBrowser.m	
@@ -87,11 +87,9 @@ - (void) setRepresentedObject: (id)representedObject
 
 - (void) awakeFromNib
 {
-    if ([self.documentationScrollView respondsToSelector: @selector(setUsesPredominantAxisScrolling:)])
-        self.documentationScrollView.usesPredominantAxisScrolling = YES;
+    self.documentationScrollView.usesPredominantAxisScrolling = YES;
     
-    if ([self.documentationScrollView respondsToSelector: @selector(setHorizontalScrollElasticity:)])
-        self.documentationScrollView.horizontalScrollElasticity = NSScrollElasticityNone;
+    self.documentationScrollView.horizontalScrollElasticity = NSScrollElasticityNone;
     
 	[self.view registerForDraggedTypes: @[NSPasteboardTypeFileURL]];
     //Allow documentation files to be dragged out of the documentation list to other applications,
@@ -195,8 +193,7 @@ - (void) _syncDocumentationURLs
             [self.delegate documentationBrowser: self didUpdateFromURLs: oldURLs toURLs: newURLs];
         
         //Flash the scrollbars (if any) to indicate that the content of the scroller has changed.
-        if ([self.documentationScrollView respondsToSelector: @selector(flashScrollers)])
-            [self.documentationScrollView flashScrollers];
+        [self.documentationScrollView flashScrollers];
     }
 }
 
@@ -837,8 +834,7 @@ - (void) _refreshIcon
             //Meanwhile, load in a quicklook preview for this file in the background.
             //Take retina displays into account when calculating the appropriate preview size.
             NSSize thumbnailSize = self.view.bounds.size;
-            if ([self.view respondsToSelector: @selector(convertSizeToBacking:)])
-                thumbnailSize = [self.view convertSizeToBacking: thumbnailSize];
+            thumbnailSize = [self.view convertSizeToBacking: thumbnailSize];
             
             //We perform this in an asynchronous block, because it can take a while
             //to prepare the thumbnail.