In fact, it places an emphasis on punishing players that don’t work cooperatively. The rate at which it moves through these three states isn’t consistent and is prone to change based on how a team of players performs. This gives you an opportunity to heal-up, reload and get those stress levels back down to normal. Lastly, there’s the cooldown, where the director waits for a time before it spawns more zombies.Knowing that the team of players are all feeling the pressure as they fight off a myriad of different enemy archetypes. Secondly, there’s the peak, where it wants to bring the tension to a head by throwing everything at you.First, there is the build-up, where it tries to increase everyone’s stress levels by attacking different targets based on a need to increase their stress.The director uses this information to move through the three states of the state machine: So if you’re picking off enemies from afar, you don’t seem too ‘stressed’, but if there’s a horde of zombies all scratching you at once, you’re probably more stressed than usual. It decides who to attack because it’s monitoring your perceived ‘stress’ level, or rather how much you’re being attacked and from how far away. The director is really just a finite state machine, much like that used for the characters in Half-Life – a topic we will return to in the future – but instead of controlling a specific character, it has two jobs: it spawns in new zombies to chase the player and also decides which specific players to target.

Left 4 dead game cover