Left 4 Dead is a co-op first person shooter focused around yourself and three others escaping various locations as hordes of zombies attack. That’s if you play as the Survivors anyway, as your other option is to take on the roles of Special Infected with the sole mission of taking out the Survivors.
Its focus is massively based around that concept of co-operative play rather than just splitting a game into teams; Valve have made it practically impossible to play without helping out your teammates.
Special Infected are a key element in Left 4 Dead’s gameplay, and feature regardless of whether you’re playing against real people or AI. The idea of these super-zombies is to force players into using more focused, deliberate tactics beyond the simple “run around and shoot anything that moves” approach.
“When someone’s being choked by a Smoker they’re going to die unless you deal with it,” explained developer Erik Johnson, “Being the person who kills the Smoker that’s going to end a person’s game is very rewarding”.
The game’s co-operative mechanics are encouraged by the choice not to have players die when their health has been depleted. Instead you’ll find yourself lying on the floor with only a pistol fighting back the Infected from the horizontal position whilst your teammates (hopefully) rush to revive you in a limited time period. It’s worth noting that it’s still possible to be properly taken out in this time period though, if say a Hunter manages to leap on you.
The aforementioned Hunters are a vicious breed that won’t let go of a player until shot off. Then there’s Tank, who as you might expect boasts a massive resilience to damage and, more surprisingly, can hurl huge objects such as cars and bits of floor in your general direction. The Boomer is a nasty piece of work who will vomit bile in order to transform you into a massive beacon the Common Infected will home in on. He’ll also explode when hit or shot, causing some pretty hefty damage to anyone nearby.
A reward system based around merits and demerits helps reinforce the friendly approach required to make your way successfully through Valve’s new shooter. Heal a friend while they’re down and you’ll receive a merit, don’t help out and they’ll end up locked in a room further on. Managing to not end up downed at any point will also land you a merit, as will totting up headshots and directly protecting players from attacks from behind.
Shoot at a zombie that ends up coming back will earn you the “Forgeful” demerit badge. There are also demerits for friendly fire but apparently Valve are acknowledging that this isn’t always a player’s fault. In practice this means that you’ll be let off when a player runs into your firing line or you were firing into a horde of Infected in which your teammate was stood, i.e. it was an accident.
The two co-operating development teams, Valve and Turtle Rock, have been developing a system that makes no two games quite alike: the AI Director. Beyond making zombies appear at varied stages of the levels the system is geared up massively to controlling the pacing of the game. The distribution of Common Infected and Special Infected is key to keeping a good balance to the levels. “One of the first demos Mike showed us had these bars that measured player stress, and that’s the thing he’s trying to control,” Johnson tells us. “If you do the same thing over and over again, no matter how well you execute on that, players aren’t switching gears enough and it gets boring, or too stressful, and the game feels cheap. ‘Combat fatigue’ is a term we use a lot when we playtest our single-player games. So Mike can watch stress levels and make sure players aren’t having high-amplitude events again and again”.
Left 4 Dead has a lot of focus in this idea of variability; no two plays will ever feel the same and there aren’t any rigid set-pieces though certain tasks will need to be performed in order to get through some specific sections.
The game is slightly more helpful to the player-controlled Infected, showing Survivors through walls with red highlights, providing arrows to guide players to them along with clues to interactive scenery. The Infected objective is to rack up as many hit points as possible throughout the match, which will give you a score come the end of a level. Playing as a Smoker enables players to stalk from the rooftops and wait for an opportune moment, preferably while one member of the group is separated, allowing you to hang a Survivor with your elongated tongue of doom.
“It’s terrifying as a player to have that happen,” Johnson tells us. “There’s nothing more fun in the game – I know Chet and I would say so anyway – than choking somebody to death as a Smoker.” “And then choking the person that comes to help them,” Faliszek adds.
The AI Director shows off its talents not only when playing against an entirely computer-controlled opposition, judging just how many times both Special and Common Infected spawn even in Vs mode. That means playing as Special Infected won’t be quite so irritating in moments where you’re killed pretty quickly, with the clever computer controller being kind to players allowing quicker respawns when it sees apt.
While you’d think the Infected would suffer the worst of that hounded down feeling, Survivors can turn the game around by using sneaky tactics. Turning off your torches and walking will make it much harder for the Infected to locate you and your teammates, as their handy building penetrating highlights will become inactive.
Left 4 Dead features a bunch of very different locations, one of which involves a path through a hospital (wherein the unaffected humans must reach the roof to be picked up by a helicopter) while another lands the Survivors in an eerie cornfield.
Levels culminate in a hectic battle of sorts which, like the rest of the game, will vary from one play to another. “They play out similarly but the terrain itself is such that they play out pretty differently,” Johnson explained. “The one where you’re on a rooftop’s tough because you can get yanked off by a Smoker, so instead of looking up you need to look down.”
Ultimately, it’s a mad-dash game of tactics and co-operative play which strays massively away from the twitch-shooting and camping so often seen in military FPSs. That said, Valve’s heavy involvement in the development process has meant that the engine (Source) feels equally matched to a multitude of more traditional shooters.
