diff --git a/osu.Game/Beatmaps/ControlPoints/ControlPointInfo.cs b/osu.Game/Beatmaps/ControlPoints/ControlPointInfo.cs
index e7035880dd..e46eb8e20a 100644
--- a/osu.Game/Beatmaps/ControlPoints/ControlPointInfo.cs
+++ b/osu.Game/Beatmaps/ControlPoints/ControlPointInfo.cs
@@ -1,6 +1,7 @@
 // Copyright (c) 2007-2017 ppy Pty Ltd <contact@ppy.sh>.
 // Licensed under the MIT Licence - https://raw.githubusercontent.com/ppy/osu/master/LICENCE
 
+using System;
 using System.Collections.Generic;
 using System.Linq;
 using osu.Framework.Lists;
@@ -85,6 +86,9 @@ namespace osu.Game.Beatmaps.ControlPoints
         private T binarySearch<T>(SortedList<T> list, double time, T prePoint = null)
             where T : ControlPoint, new()
         {
+            if (list == null)
+                throw new ArgumentNullException(nameof(list));
+
             if (list.Count == 0)
                 return new T();
 
diff --git a/osu.Game/Beatmaps/Drawables/BeatmapBackgroundSprite.cs b/osu.Game/Beatmaps/Drawables/BeatmapBackgroundSprite.cs
index 9b897b4912..0ac8d12591 100644
--- a/osu.Game/Beatmaps/Drawables/BeatmapBackgroundSprite.cs
+++ b/osu.Game/Beatmaps/Drawables/BeatmapBackgroundSprite.cs
@@ -1,6 +1,7 @@
 // Copyright (c) 2007-2017 ppy Pty Ltd <contact@ppy.sh>.
 // Licensed under the MIT Licence - https://raw.githubusercontent.com/ppy/osu/master/LICENCE
 
+using System;
 using osu.Framework.Allocation;
 using osu.Framework.Graphics.Sprites;
 
@@ -12,6 +13,9 @@ namespace osu.Game.Beatmaps.Drawables
 
         public BeatmapBackgroundSprite(WorkingBeatmap working)
         {
+             if (working == null)
+                 throw new ArgumentNullException(nameof(working));
+
             this.working = working;
         }
 
diff --git a/osu.Game/Beatmaps/Drawables/BeatmapGroup.cs b/osu.Game/Beatmaps/Drawables/BeatmapGroup.cs
index 6e5af29799..163dd7fbe9 100644
--- a/osu.Game/Beatmaps/Drawables/BeatmapGroup.cs
+++ b/osu.Game/Beatmaps/Drawables/BeatmapGroup.cs
@@ -72,6 +72,11 @@ namespace osu.Game.Beatmaps.Drawables
 
         public BeatmapGroup(BeatmapSetInfo beatmapSet, BeatmapManager manager)
         {
+            if (beatmapSet == null)
+                throw new ArgumentNullException(nameof(beatmapSet));
+            if (manager == null)
+                throw new ArgumentNullException(nameof(manager));
+
             BeatmapSet = beatmapSet;
             WorkingBeatmap beatmap = manager.GetWorkingBeatmap(BeatmapSet.Beatmaps.FirstOrDefault());
 
diff --git a/osu.Game/Beatmaps/Drawables/BeatmapPanel.cs b/osu.Game/Beatmaps/Drawables/BeatmapPanel.cs
index c0705d8f61..e6bf08eb9f 100644
--- a/osu.Game/Beatmaps/Drawables/BeatmapPanel.cs
+++ b/osu.Game/Beatmaps/Drawables/BeatmapPanel.cs
@@ -73,6 +73,9 @@ namespace osu.Game.Beatmaps.Drawables
 
         public BeatmapPanel(BeatmapInfo beatmap)
         {
+            if (beatmap == null)
+                throw new ArgumentNullException(nameof(beatmap));
+
             Beatmap = beatmap;
             Height *= 0.60f;
 
diff --git a/osu.Game/Beatmaps/Drawables/BeatmapSetCover.cs b/osu.Game/Beatmaps/Drawables/BeatmapSetCover.cs
index df7e0905d0..614ebc236b 100644
--- a/osu.Game/Beatmaps/Drawables/BeatmapSetCover.cs
+++ b/osu.Game/Beatmaps/Drawables/BeatmapSetCover.cs
@@ -1,6 +1,7 @@
 // Copyright (c) 2007-2017 ppy Pty Ltd <contact@ppy.sh>.
 // Licensed under the MIT Licence - https://raw.githubusercontent.com/ppy/osu/master/LICENCE
 
+using System;
 using osu.Framework.Allocation;
 using osu.Framework.Graphics.Sprites;
 using osu.Framework.Graphics.Textures;
@@ -12,6 +13,9 @@ namespace osu.Game.Beatmaps.Drawables
         private readonly BeatmapSetInfo set;
         public BeatmapSetCover(BeatmapSetInfo set)
         {
+            if (set == null)
+                throw new ArgumentNullException(nameof(set));
+
             this.set = set;
         }
 
diff --git a/osu.Game/Beatmaps/Drawables/BeatmapSetHeader.cs b/osu.Game/Beatmaps/Drawables/BeatmapSetHeader.cs
index ee75b77747..8a589ccd30 100644
--- a/osu.Game/Beatmaps/Drawables/BeatmapSetHeader.cs
+++ b/osu.Game/Beatmaps/Drawables/BeatmapSetHeader.cs
@@ -36,6 +36,9 @@ namespace osu.Game.Beatmaps.Drawables
 
         public BeatmapSetHeader(WorkingBeatmap beatmap)
         {
+            if (beatmap == null)
+                throw new ArgumentNullException(nameof(beatmap));
+
             this.beatmap = beatmap;
 
             Children = new Drawable[]
@@ -88,6 +91,9 @@ namespace osu.Game.Beatmaps.Drawables
         [BackgroundDependencyLoader]
         private void load(LocalisationEngine localisation)
         {
+            if (localisation == null)
+                throw new ArgumentNullException(nameof(localisation));
+
             title.Current = localisation.GetUnicodePreference(beatmap.Metadata.TitleUnicode, beatmap.Metadata.Title);
             artist.Current = localisation.GetUnicodePreference(beatmap.Metadata.ArtistUnicode, beatmap.Metadata.Artist);
         }
@@ -154,6 +160,9 @@ namespace osu.Game.Beatmaps.Drawables
 
         public void AddDifficultyIcons(IEnumerable<BeatmapPanel> panels)
         {
+            if (panels == null)
+                throw new ArgumentNullException(nameof(panels));
+
             foreach (var p in panels)
                 difficultyIcons.Add(new DifficultyIcon(p.Beatmap));
         }
diff --git a/osu.Game/Beatmaps/Drawables/DifficultyColouredContainer.cs b/osu.Game/Beatmaps/Drawables/DifficultyColouredContainer.cs
index 41b77f6584..57a5abc4c7 100644
--- a/osu.Game/Beatmaps/Drawables/DifficultyColouredContainer.cs
+++ b/osu.Game/Beatmaps/Drawables/DifficultyColouredContainer.cs
@@ -1,6 +1,7 @@
 // Copyright (c) 2007-2017 ppy Pty Ltd <contact@ppy.sh>.
 // Licensed under the MIT Licence - https://raw.githubusercontent.com/ppy/osu/master/LICENCE
 
+using System;
 using osu.Framework.Allocation;
 using osu.Framework.Graphics.Containers;
 using osu.Game.Graphics;
@@ -23,6 +24,9 @@ namespace osu.Game.Beatmaps.Drawables
         [BackgroundDependencyLoader]
         private void load(OsuColour palette)
         {
+            if (palette == null)
+                throw new ArgumentNullException(nameof(palette));
+
             this.palette = palette;
             AccentColour = getColour(beatmap);
         }
@@ -39,6 +43,9 @@ namespace osu.Game.Beatmaps.Drawables
 
         private DifficultyRating getDifficultyRating(BeatmapInfo beatmap)
         {
+            if (beatmap == null)
+                throw new ArgumentNullException(nameof(beatmap));
+
             var rating = beatmap.StarDifficulty;
 
             if (rating < 1.5) return DifficultyRating.Easy;
diff --git a/osu.Game/Beatmaps/Drawables/DifficultyIcon.cs b/osu.Game/Beatmaps/Drawables/DifficultyIcon.cs
index 1aff764ede..8259da9492 100644
--- a/osu.Game/Beatmaps/Drawables/DifficultyIcon.cs
+++ b/osu.Game/Beatmaps/Drawables/DifficultyIcon.cs
@@ -1,6 +1,7 @@
 // Copyright (c) 2007-2017 ppy Pty Ltd <contact@ppy.sh>.
 // Licensed under the MIT Licence - https://raw.githubusercontent.com/ppy/osu/master/LICENCE
 
+using System;
 using osu.Framework.Allocation;
 using osu.Framework.Graphics;
 using osu.Game.Graphics;
@@ -15,6 +16,9 @@ namespace osu.Game.Beatmaps.Drawables
 
         public DifficultyIcon(BeatmapInfo beatmap) : base(beatmap)
         {
+            if (beatmap == null)
+                throw new ArgumentNullException(nameof(beatmap));
+
             this.beatmap = beatmap;
             Size = new Vector2(20);
         }
diff --git a/osu.Game/Beatmaps/Formats/BeatmapDecoder.cs b/osu.Game/Beatmaps/Formats/BeatmapDecoder.cs
index 962c6ad49a..7e1a87085c 100644
--- a/osu.Game/Beatmaps/Formats/BeatmapDecoder.cs
+++ b/osu.Game/Beatmaps/Formats/BeatmapDecoder.cs
@@ -18,6 +18,9 @@ namespace osu.Game.Beatmaps.Formats
 
         public static BeatmapDecoder GetDecoder(StreamReader stream)
         {
+            if (stream == null)
+                throw new ArgumentNullException(nameof(stream));
+
             string line;
             do { line = stream.ReadLine()?.Trim(); }
             while (line != null && line.Length == 0);
diff --git a/osu.Game/Beatmaps/Formats/OsuLegacyDecoder.cs b/osu.Game/Beatmaps/Formats/OsuLegacyDecoder.cs
index d775ab409b..11631e9447 100644
--- a/osu.Game/Beatmaps/Formats/OsuLegacyDecoder.cs
+++ b/osu.Game/Beatmaps/Formats/OsuLegacyDecoder.cs
@@ -70,6 +70,11 @@ namespace osu.Game.Beatmaps.Formats
 
         private void handleGeneral(Beatmap beatmap, string line)
         {
+            if (beatmap == null)
+                throw new ArgumentNullException(nameof(beatmap));
+            if (line == null)
+                throw new ArgumentNullException(nameof(line));
+
             var pair = splitKeyVal(line, ':');
 
             var metadata = beatmap.BeatmapInfo.Metadata;
@@ -129,6 +134,11 @@ namespace osu.Game.Beatmaps.Formats
 
         private void handleEditor(Beatmap beatmap, string line)
         {
+            if (beatmap == null)
+                throw new ArgumentNullException(nameof(beatmap));
+            if (line == null)
+                throw new ArgumentNullException(nameof(line));
+
             var pair = splitKeyVal(line, ':');
 
             switch (pair.Key)
@@ -153,6 +163,11 @@ namespace osu.Game.Beatmaps.Formats
 
         private void handleMetadata(Beatmap beatmap, string line)
         {
+            if (beatmap == null)
+                throw new ArgumentNullException(nameof(beatmap));
+            if (line == null)
+                throw new ArgumentNullException(nameof(line));
+
             var pair = splitKeyVal(line, ':');
 
             var metadata = beatmap.BeatmapInfo.Metadata;
@@ -194,6 +209,11 @@ namespace osu.Game.Beatmaps.Formats
 
         private void handleDifficulty(Beatmap beatmap, string line)
         {
+            if (beatmap == null)
+                throw new ArgumentNullException(nameof(beatmap));
+            if (line == null)
+                throw new ArgumentNullException(nameof(line));
+
             var pair = splitKeyVal(line, ':');
 
             var difficulty = beatmap.BeatmapInfo.BaseDifficulty;
@@ -226,6 +246,9 @@ namespace osu.Game.Beatmaps.Formats
         /// <param name="line">The line which may contains variables.</param>
         private void decodeVariables(ref string line)
         {
+            if (line == null)
+                throw new ArgumentNullException(nameof(line));
+
             while (line.IndexOf('$') >= 0)
             {
                 string origLine = line;
@@ -244,6 +267,11 @@ namespace osu.Game.Beatmaps.Formats
 
         private void handleEvents(Beatmap beatmap, string line, ref StoryboardSprite storyboardSprite, ref CommandTimelineGroup timelineGroup)
         {
+            if (line == null)
+                throw new ArgumentNullException(nameof(line));
+            if (beatmap == null)
+                throw new ArgumentNullException(nameof(beatmap));
+
             var depth = 0;
             while (line.StartsWith(" ") || line.StartsWith("_"))
             {
@@ -469,6 +497,11 @@ namespace osu.Game.Beatmaps.Formats
 
         private void handleTimingPoints(Beatmap beatmap, string line)
         {
+            if (beatmap == null)
+                throw new ArgumentNullException(nameof(beatmap));
+            if (line == null)
+                throw new ArgumentNullException(nameof(line));
+
             string[] split = line.Split(',');
 
             double time = double.Parse(split[0].Trim(), NumberFormatInfo.InvariantInfo);
@@ -555,6 +588,11 @@ namespace osu.Game.Beatmaps.Formats
 
         private void handleColours(Beatmap beatmap, string line, ref bool hasCustomColours)
         {
+            if (beatmap == null)
+                throw new ArgumentNullException(nameof(beatmap));
+            if (line == null)
+                throw new ArgumentNullException(nameof(line));
+
             var pair = splitKeyVal(line, ':');
 
             string[] split = pair.Value.Split(',');
@@ -587,6 +625,9 @@ namespace osu.Game.Beatmaps.Formats
 
         private void handleVariables(string line)
         {
+            if (line == null)
+                throw new ArgumentNullException(nameof(line));
+
             var pair = splitKeyVal(line, '=');
             variables[pair.Key] = pair.Value;
         }
@@ -603,6 +644,11 @@ namespace osu.Game.Beatmaps.Formats
 
         protected override void ParseFile(StreamReader stream, Beatmap beatmap)
         {
+            if (beatmap == null)
+                throw new ArgumentNullException(nameof(beatmap));
+            if (stream == null)
+                throw new ArgumentNullException(nameof(stream));
+
             beatmap.BeatmapInfo.BeatmapVersion = beatmapVersion;
 
             Section section = Section.None;
@@ -679,6 +725,9 @@ namespace osu.Game.Beatmaps.Formats
 
         private KeyValuePair<string, string> splitKeyVal(string line, char separator)
         {
+            if (line == null)
+                throw new ArgumentNullException(nameof(line));
+
             var split = line.Trim().Split(new[] { separator }, 2);
 
             return new KeyValuePair<string, string>
diff --git a/osu.Game/Users/Avatar.cs b/osu.Game/Users/Avatar.cs
index 111c901ca0..7ced0305fd 100644
--- a/osu.Game/Users/Avatar.cs
+++ b/osu.Game/Users/Avatar.cs
@@ -1,6 +1,7 @@
 // Copyright (c) 2007-2017 ppy Pty Ltd <contact@ppy.sh>.
 // Licensed under the MIT Licence - https://raw.githubusercontent.com/ppy/osu/master/LICENCE
 
+using System;
 using osu.Framework.Allocation;
 using osu.Framework.Graphics;
 using osu.Framework.Graphics.Containers;
@@ -25,6 +26,9 @@ namespace osu.Game.Users
         [BackgroundDependencyLoader]
         private void load(TextureStore textures)
         {
+            if (textures == null)
+                throw new ArgumentNullException(nameof(textures));
+
             Texture texture = null;
             if (user != null && user.Id > 1) texture = textures.Get($@"https://a.ppy.sh/{user.Id}");
             if (texture == null) texture = textures.Get(@"Online/avatar-guest");
diff --git a/osu.Game/Users/Country.cs b/osu.Game/Users/Country.cs
index bf06d9f8bc..0c0d12c1cc 100644
--- a/osu.Game/Users/Country.cs
+++ b/osu.Game/Users/Country.cs
@@ -1,6 +1,7 @@
 // Copyright (c) 2007-2017 ppy Pty Ltd <contact@ppy.sh>.
 // Licensed under the MIT Licence - https://raw.githubusercontent.com/ppy/osu/master/LICENCE
 
+using System;
 using Newtonsoft.Json;
 using osu.Framework.Allocation;
 using osu.Framework.Graphics;
@@ -45,6 +46,9 @@ namespace osu.Game.Users
         [BackgroundDependencyLoader]
         private void load(TextureStore ts)
         {
+            if (ts == null)
+                throw new ArgumentNullException(nameof(ts));
+
             textures = ts;
             sprite.Texture = textures.Get($@"Flags/{flagName}");
         }
diff --git a/osu.Game/Users/UserCoverBackground.cs b/osu.Game/Users/UserCoverBackground.cs
index c0f0d09d9d..68c97fc8fd 100644
--- a/osu.Game/Users/UserCoverBackground.cs
+++ b/osu.Game/Users/UserCoverBackground.cs
@@ -1,6 +1,7 @@
 // Copyright (c) 2007-2017 ppy Pty Ltd <contact@ppy.sh>.
 // Licensed under the MIT Licence - https://raw.githubusercontent.com/ppy/osu/master/LICENCE
 
+using System;
 using osu.Framework.Allocation;
 using osu.Framework.Graphics.Sprites;
 using osu.Framework.Graphics.Textures;
@@ -19,6 +20,9 @@ namespace osu.Game.Users
         [BackgroundDependencyLoader]
         private void load(TextureStore textures)
         {
+            if (textures == null)
+                throw new ArgumentNullException(nameof(textures));
+
             if (!string.IsNullOrEmpty(user.CoverUrl))
                 Texture = textures.Get(user.CoverUrl);
         }
diff --git a/osu.Game/Users/UserPanel.cs b/osu.Game/Users/UserPanel.cs
index e5518b5845..706ad86bfc 100644
--- a/osu.Game/Users/UserPanel.cs
+++ b/osu.Game/Users/UserPanel.cs
@@ -38,6 +38,9 @@ namespace osu.Game.Users
 
         public UserPanel(User user)
         {
+            if (user == null)
+                throw new ArgumentNullException(nameof(user));
+
             this.user = user;
 
             Height = height - status_height;
@@ -173,6 +176,9 @@ namespace osu.Game.Users
         [BackgroundDependencyLoader(permitNulls: true)]
         private void load(OsuColour colours, UserProfileOverlay profile)
         {
+            if (colours == null)
+                throw new ArgumentNullException(nameof(colours));
+
             Status.ValueChanged += displayStatus;
             Status.ValueChanged += status => statusBg.FadeColour(status?.GetAppropriateColour(colours) ?? colours.Gray5, 500, Easing.OutQuint);