The basic gameplay setup is defined by the [[Game Mode]], the [[Game State]], the [[Pawn]], the [[Player Controller]], the [[Player State]], and [[HUD]].
At any point in time during gameplay a single [[Game Mode]] is active. The [[Game Mode]] define which [[Game State]], [[Pawn]], [[Player Controller]], [[Player State]], and [[HUD]] to use.
The project has a default [[Game Mode]] set in Project Settings > Maps & Modes > Default Game Mode.
A Level may override the default [[Game Mode]] in Main Tool Bar > Settings > World Settings > Game Mode > Game Mode Override.