ABSTRACT
Paragon is a multiplayer online battle arena (MOBA)-type game developed by Epic Games, built with Unreal Engine 4 (UE4). This chapter describes some of the extensions made to the vanilla UE4 AI systems as well as some of the simple systems tailored specifically for Paragon player bots. In Paragon, players control heroes. A hero is a character on a team that can use abilities to debuff or deal damage to enemy characters and structures, or to buff his or hers own teammates. An experienced AI developer might be surprised that all Paragon bots use the same behavior tree. In UE4, the spatial querying system (EQS) is the AI's spatial querying solution and is mentioned since it is mostly used by the Behavior Trees (BTs) to generate and use runtime spatial information. The Ability Picker is a simple yet surprisingly powerful service that is responsible for picking the right ability from a set of given abilities, given a certain target.
