It is, but a lot of in-game object behaviors (and almost all modding) was done in &quot;UnrealScript&quot;, a sort of java like language that compiles to bytecode.<p><a href="https:&#x2F;&#x2F;ardvaark.net&#x2F;unrealscript-and-domainspecific-languages" rel="nofollow">https:&#x2F;&#x2F;ardvaark.net&#x2F;unrealscript-and-domainspecific-languag...</a><p>UE4 seems to have more complex scripting capabilities:<p>&gt; UE4 also includes new developer features to reduce iteration time, and allows updating of C++ code while the engine is running. The new &quot;Blueprint&quot; visual scripting system (a successor to UE3&#x27;s &quot;Kismet&quot;[80]) allows for rapid development of game logic without using C++, and includes live debugging.[81][82]