Use of Graph Theory in Video Game Artificial Intelligence for Promoting Replay Value Case Study: “AI Director” of Valve’s Left 4 Dead Alvin Natwiguna - 13512030 Program Studi Teknik Informatika Sekolah Teknik Elektro dan Informatika Institut Teknologi Bandung, Jl. Ganesha 10 Bandung 40132, Indonesia
[email protected] Abstract—One of the main factors that makes a video game The Infected is split to two types, the Normal Infected – as a product – has a long life cycle is its replay value. Replay and the Special Infected. The Normal Infected are zombies value describes the ‘depth’ of an entertainment medium; in that attack at close range. Each has a low pool of health, this case, a video game. Besides the content of the game, one but they sometimes attack in large mobs. The Special of the main factors that influences a video game’s replay value is the system on which the video game is built upon. This Infected are zombies that have special features which paper will discuss the use of graph theory in explaining makes them quite deadly to the survivors. For example, the Valve’s Left 4 Dead artificial intelligence system – the “AI Tank has a monstrous, large body capable of taking large Director” – that promotes its replay value. amount of damage, punching cars and throwing a large chunk of rock to the survivors. It also has a deadly punch Index Terms—Artificial Intelligence, Graph, Left 4 Dead, that can incapacitate a survivor in one hit. Special Infected Replay Value. is further divided to normal and boss infected, based on how frequently they spawn, i.e.