diff --git a/lua/gluatest/expectations/negative.lua b/lua/gluatest/expectations/negative.lua
index b5a938f5..fad5bef3 100644
--- a/lua/gluatest/expectations/negative.lua
+++ b/lua/gluatest/expectations/negative.lua
@@ -3,6 +3,7 @@ local TypeID = TypeID
 local IsValid = IsValid
 local isstring = isstring
 local string_format = string.format
+local Arg = include( "arg.lua" )
 local GetDiff = include( "utils/table_diff.lua" )
 
 -- Inverse checks
@@ -231,10 +232,53 @@ return function( subject, ... )
         end
     end
 
+    --- @deprecated
     function expectations.haveBeenCalled()
         GLuaTest.DeprecatedNotice( "to.haveBeenCalled()", "was.called()" )
         return expectations.called()
     end
 
+    --- Checks if the given argument is equal to the expected argument
+    --- Or, if the expected argument is an argument matcher, checks if the given argument matches the matcher
+    --- @param givenArg any The argument that was given to the stub
+    --- @param expectedArg any The expected argument, which can be a matcher or a value
+    local function checkArg( givenArg, expectedArg )
+        if givenArg == expectedArg then return true end
+
+        if Arg.IsArgMatcher( expectedArg ) then
+            local argMatcher = expectedArg --[[@as GLuaTest_StubArg]]
+            return argMatcher.check( givenArg )
+        end
+
+        return false
+    end
+
+    --- Expects the subject stub to have not been called with exactly the given arguments
+    --- @param ... any
+    function expectations.calledWith( ... )
+        assert( subject.IsStub, ".calledWith expects a stub" )
+        --- @cast subject GLuaTest_Stub
+
+        local expected = { ... }
+
+        for _, call in ipairs( subject.callHistory or {} ) do
+            if #call == #expected then
+                local match = true
+
+                for k = 1, #expected do
+                    if not checkArg( call[k], expected[k] ) then
+                        match = false
+                        break
+                    end
+                end
+
+                if match then
+                    local formattedArgs = table.concat( expected, ", " )
+                    i.expected( "to not have been called with arguments: %s", formattedArgs )
+                end
+            end
+        end
+    end
+
     return expectations
 end
diff --git a/lua/gluatest/expectations/positive.lua b/lua/gluatest/expectations/positive.lua
index 92464d9b..b9779ab2 100644
--- a/lua/gluatest/expectations/positive.lua
+++ b/lua/gluatest/expectations/positive.lua
@@ -3,6 +3,7 @@ local TypeID = TypeID
 local IsValid = IsValid
 local isstring = isstring
 local string_format = string.format
+local Arg = include( "arg.lua" )
 local GetDiff = include( "utils/table_diff.lua" )
 
 -- Positive checks
@@ -220,9 +221,10 @@ return function( subject, ... )
     end
 
     --- Expects the subject stub to have been called, optionally with an expected number of calls
-    --- @param n? number
+    --- @param n? number Expected number of calls, if nil then expects at least one call
     function expectations.called( n )
         assert( subject.IsStub, ".called expects a stub" )
+        --- @cast subject GLuaTest_Stub
 
         local callCount = subject.callCount
 
@@ -237,15 +239,54 @@ return function( subject, ... )
         end
     end
 
+    --- @deprecated
     function expectations.haveBeenCalled( n )
         GLuaTest.DeprecatedNotice( "to.haveBeenCalled( number )", "was.called( number )" )
         return expectations.called( n )
     end
 
-    -- Soon..
-    --
-    -- function expectations.haveBeenCalledWith( ... )
-    -- end
+    -- Called Expectations
+
+    --- Checks if the given argument is equal to the expected argument
+    --- Or, if the expected argument is an argument matcher, checks if the given argument matches the matcher
+    --- @param givenArg any The argument that was given to the stub
+    --- @param expectedArg any The expected argument, which can be a matcher or a value
+    local function checkArg( givenArg, expectedArg )
+        if givenArg == expectedArg then return true end
+
+        if Arg.IsArgMatcher( expectedArg ) then
+            local argMatcher = expectedArg --[[@as GLuaTest_StubArg]]
+            return argMatcher.check( givenArg )
+        end
+
+        return false
+    end
+
+    --- Expects the subject stub to have been called with exactly the given arguments
+    --- @param ... any
+    function expectations.calledWith( ... )
+        assert( subject.IsStub, ".calledWith expects a stub" )
+        --- @cast subject GLuaTest_Stub
+
+        local expected = { ... }
+
+        for _, call in ipairs( subject.callHistory or {} ) do
+            if #call == #expected then
+                local match = true
+
+                for k = 1, #expected do
+                    if not checkArg( call[k], expected[k] ) then
+                        match = false
+                        break
+                    end
+                end
+
+                if match then return end
+            end
+        end
+
+        i.expected( "to have been called with arguments: %s", table.concat( expected, ", " ) )
+    end
 
     return expectations
 end
diff --git a/lua/gluatest/init.lua b/lua/gluatest/init.lua
index d6303149..7497dfd1 100644
--- a/lua/gluatest/init.lua
+++ b/lua/gluatest/init.lua
@@ -35,7 +35,7 @@ GLuaTest = {
         AddCSLuaFile( "gluatest/utils/version.lua" )
 
         -- /stubs/*
-        AddCSLuaFile( "gluatest/stubs/stub_maker.lua" )
+        AddCSLuaFile( "gluatest/stubs/stubMaker.lua" )
 
         -- /runner/*
         AddCSLuaFile( "gluatest/runner/colors.lua" )
diff --git a/lua/gluatest/runner/helpers.lua b/lua/gluatest/runner/helpers.lua
index 9f6536af..3c4ecb08 100644
--- a/lua/gluatest/runner/helpers.lua
+++ b/lua/gluatest/runner/helpers.lua
@@ -8,7 +8,7 @@ local Helpers = {
 local expect = include( "gluatest/expectations/expect.lua" )
 
 --- @type GLuaTest_StubMaker
-local stubMaker = include( "gluatest/stubs/stub_maker.lua" )
+local stubMaker = include( "gluatest/stubs/stubMaker.lua" )
 
 --- Gets a unique case ID
 --- @return string
diff --git a/lua/gluatest/stubs/arg.lua b/lua/gluatest/stubs/arg.lua
new file mode 100644
index 00000000..863ef80d
--- /dev/null
+++ b/lua/gluatest/stubs/arg.lua
@@ -0,0 +1,197 @@
+local argMeta = {
+    __tostring = function( self )
+        return "Arg Matcher: " .. self.name
+    end,
+}
+
+--- Creates a new argument matcher
+--- @param name string The name of the matcher (for use in error messages)
+--- @param check fun(any): boolean A function that returns true if the argument matches
+local function New( name, check )
+    --- @class GLuaTest_StubArg
+    local arg = {
+        --- @type string
+        --- The name of the matcher, used in error messages
+        name = name,
+
+        --- A function that returns true if the argument matches
+        check = check,
+    }
+
+    return setmetatable( arg, argMeta )
+end
+
+--- @alias GLuaTest_StubArg_Matcher fun(any): boolean
+
+--- @class GLuaTest_StubArgs
+local Arg = {
+    --- The metatable for all argument matchers
+    argMeta = argMeta,
+
+    New = New,
+
+    --- Checks if the given argument is an argument matcher
+    --- @param arg any The argument to check
+    IsArgMatcher = function( arg )
+        return getmetatable( arg ) == argMeta
+    end,
+
+    --- Matches any argument
+    Any = New( "Any", function( _ )
+        return true
+    end ),
+
+    --- Matches nil
+    Nil = New( "Nil", function( arg )
+        return arg == nil
+    end ),
+
+    --- Matches any boolean
+    Boolean = New( "Any Boolean", function( arg )
+        return arg == true or arg == false
+    end ),
+
+    --- Matches any number
+    Number = New( "Any Number", function( arg )
+        return type( arg ) == "number"
+    end ),
+
+    --- Matches any string
+    String = New( "Any String", function( arg )
+        return type( arg ) == "string"
+    end ),
+
+    --- Matches any table
+    Table = New( "Any Table", function( arg )
+        return type( arg ) == "table"
+    end ),
+
+    --- Matches any function
+    Function = New( "Any Function", function( arg )
+        return type( arg ) == "function"
+    end ),
+
+    --- Matches any userdata
+    Userdata = New( "Any Userdata", function( arg )
+        return type( arg ) == "userdata"
+    end ),
+
+    --- Matches any thread
+    Thread = New( "Any Thread", function( arg )
+        return type( arg ) == "thread"
+    end ),
+
+    -- GMod Types
+
+    --- Matches any Vector
+    Vector = New( "Any Vector", function( arg )
+        return type( arg ) == "Vector"
+    end ),
+
+    --- Matches any Angle
+    Angle = New( "Any Angle", function( arg )
+        return type( arg ) == "Angle"
+    end ),
+
+    --- Matches any Color
+    Color = New( "Any Color", function( arg )
+        return debug.getmetatable( arg ) == FindMetaTable( "Color" )
+    end ),
+
+    --- Matches any VMatrix
+    Matrix = New( "Any Matrix", function( arg )
+        return type( arg ) == "VMatrix"
+    end ),
+
+    --- Matches any Entity
+    Entity = New( "Any Entity", function( arg )
+        return type( arg ) == "Entity"
+    end ),
+
+    --- Matches any Player
+    Player = New( "Any Player", function( arg )
+        return type( arg ) == "Player"
+    end ),
+
+    --- Matches any Weapon
+    Weapon = New( "Any Weapon", function( arg )
+        return type( arg ) == "Weapon"
+    end ),
+
+    --- Matches any Vehicle
+    Vehicle = New( "Any Vehicle", function( arg )
+        return type( arg ) == "Vehicle"
+    end ),
+
+    --- Matches any Material
+    Material = New( "Any Material", function( arg )
+        return type( arg ) == "IMaterial"
+    end ),
+
+    --- Matches any PhysObj
+    PhysObj = New( "Any PhysObj", function( arg )
+        return type( arg ) == "PhysObj"
+    end ),
+
+    --- Matches any CTakeDamageInfo
+    DamageInfo = New( "Any CTakeDamageInfo", function( arg )
+        return type( arg ) == "CTakeDamageInfo"
+    end ),
+
+    --- Matches any CMoveData
+    MoveData = New( "Any CMoveData", function( arg )
+        return type( arg ) == "CMoveData"
+    end ),
+
+    --- Matches any CUserCmd
+    UserCmd = New( "Any CUserCmd", function( arg )
+        return type( arg ) == "CUserCmd"
+    end ),
+
+    --- Matches any CSoundPatch
+    SoundPatch = New( "Any CSoundPatch", function( arg )
+        return type( arg ) == "CSoundPatch"
+    end ),
+
+    --- Matches any File
+    File = New( "Any File", function( arg )
+        -- Apparently if the file doesn't exist, type( arg) will return "no value" ?
+        return type( arg ) == "File"
+    end ),
+
+    --- Matches any SurfaceInfo
+    SurfaceInfo = New( "Any SurfaceInfo", function( arg )
+        return type( arg ) == "SurfaceInfo"
+    end ),
+
+    --- Matches any ConVar
+    ConVar = New( "Any ConVar", function( arg )
+        return type( arg ) == "ConVar"
+    end ),
+
+
+    -- Clientside
+
+
+    --- Matches any Panel
+    Panel = New( "Any Panel", function( arg )
+        return type( arg ) == "Panel"
+    end ),
+
+    --- Matches any CLuaParticle
+    Particle = New( "Any Particle", function( arg )
+        return type( arg ) == "CLuaParticle"
+    end ),
+
+    --- Matches any CLuaEmitter
+    ParticleEmitter = New( "Any ParticleEmitter", function( arg )
+        return type( arg ) == "CLuaEmitter"
+    end ),
+
+    --- Matches any IMesh
+    Mesh = New( "Any Mesh", function( arg )
+        return type( arg ) == "IMesh"
+    end ),
+}
+
+return Arg
diff --git a/lua/gluatest/stubs/stub_maker.lua b/lua/gluatest/stubs/stubMaker.lua
similarity index 100%
rename from lua/gluatest/stubs/stub_maker.lua
rename to lua/gluatest/stubs/stubMaker.lua