You can't swing an undead cat without headshotting a cooperative zombie killing game. And that's a good thing. Because these games don't just teach us how to respond to a zombie apocalypse. They also teach us the single most essential lesson when it comes to surviving any real-world outbreak of horror tropes: that we have to stick together or those things out there will get us.

But all the choice can be confusing. Do you hone your reflexes in Left 4 Dead, level up your weapons in Resident Evil 5, or perfect your stance in House of the Dead: Overkill? Does Call of Duty: World at War have any contemporary relevance? Do Gears of War 2, Resistance 2, and Halo 3 even count*? We've put ten cooperative zombie killing games through their paces, ranked them, and then scored them. When it comes to deciding which collaborative re-murder simulator is the one for you and your friend(s), look no further than beyond the jump. And remember: friends don't let friends slay zombies solo.

After the jump, read Fidgit's official guide to cooperative zombie killing games.

* The answer to that consists of a no and two yeses, but not necessarily in that order.

Presented here are the ten games I tested with the help of my friends. I made sure to include people you would normally have to kill zombies with, including the spunky chick, the bigot, and the psycho who loses it. After extensive testing, I then ranked each of the ten games in the following categories: historical accuracy, intensity, tactical nuance, gore and cussing, added value, and local multiplayer support. I then awarded each game points based on how it ranked in each category. First place got ten points, second place got nine points, and so on, down to a single point for 10th place. Here are the ten cooperative zombie killing games in order of how they scored.

10. Zombie Wranglers

• Historical accuracy: 5th place
• Intensity: 10th place
• Tactical nuance: 9th place
• Gore and cussing: 10th place
• Added value: 9th place
• Local multiplayer support: 7th place
• Total score: 16 points

This underwhelming and kinder, gentler game encourages you to vacuum up the zombies instead of killing them. Who ever heard of such a thing? You do not vacuum up zombies and save them for scientific study, or whatever's going on in this cutesy Xbox Live Arcade game suitable for kids. Zombies are supposed to be shot, preferably in the head, and ideally with loads of blood, viscera, and dismemberment.

9. Killing Floor

• Historical accuracy: 6th place
• Intensity: 6th place
• Tactical nuance: 7th place
• Gore and cussing: 5th place
• Added value: 10th place
• Local multiplayer support: 9th place
• Total score: 23 points

I'm surprised this one placed so low, since it's a pretty solid co-op game with excellent and varied pacing. But its score was hurt by the fact that there's nothing to it beyond the multiplayer game. Furthermore, there's no way to play it with friends who aren't online (unless you buy multiple copies and have multiple computers).

8. Resistance 2

• Historical accuracy: 9th place
• Intensity: 3rd place
• Tactical nuance: 5th place
• Gore and cussing: 8th place
• Added value: 7th place
• Local multiplayer support: 8th place
• Total score: 26 points

The co-op gameplay is one of Resistance 2's strongest points, with distinct player classes and abilities, and with some really intense and epic battles. However, it has a very limited claim to being a zombie game. The "grims", as they're called, are very clearly zombies, but they only make occasional appearances in the game. Hence placing so low in the historical accuracy category.

7. Gears of War 2

• Historical accuracy: 10th place
• Intensity: 8th place
• Tactical nuance: 3rd place
• Gore and cussing: 6th place
• Added value: 6th place
• Local multiplayer support: 2nd place
• Total score: 32 points

I know, I know, it's a stretch to include this among zombie games. Hence coming in last place for historical accuracy. But there is something zombie-like about Gears' horde mode, in which you and up to four friends face off against waves of monsters. There are very few games that so well replicate you and a buddy staving off besieging monsters. Just pretend they're zombies and you'll be happy.

6. Left 4 Dead

• Historical accuracy: 3rd place
• Intensity: 1st place
• Tactical nuance: 8th place
• Gore and cussing: 2nd place
• Added value: 8th place
• Local multiplayer support: 10th place
• Total score: 34 points

Left 4 Dead easily takes the intensity cake. In fact, for some zombie-killing aficionados, its overbearing pace might be a liability. The game plays like a cross between Serious Sam and a mad dash. It's definitely not a traditional zombie stand-off. Still, the cast of characters gives it a great deal of historical accuracy, as these are indeed the kinds of people who fight zombies.

5. Monster Madness

• Historical accuracy: 4th place
• Intensity: 5th place
• Tactical nuance: 6th place
• Gore and cussing: 9th place
• Added value: 3rd place
• Local multiplayer support: 5th place
• Total score: 35 points

Monster Madness, both the Xbox 360 and Playstation 3 versions, ranks this high by virtue of doing a lot of things fairly well. It gets the zombie slaying aspect right, it has a lot of varied weaponry, there's an addicting RPG system, and it's great for playing with up to four friends on the same system. Just keep in mind that if any single category is most important to you, there might be better choices than Monster Madness.

4. Burn Zombie Burn

• Historical accuracy: 8th place
• Intensity: 2nd place
• Tactical nuance: 8th place
• Gore and cussing: 7th place
• Added value: 4th place
• Local multiplayer support: 6th place
• Total score: 37 points

Although it works great in co-op mode, it's mainly a puzzle game based on keeping as many zombies burning as you can. It ranks high on the intensity scale, but with the caveat that it's largely Geometry Wars-style arcade intensity.

3. Call of Duty: World at War

• Historical accuracy: 2nd place
• Intensity: 9th place
• Tactical nuance: 4th place
• Gore and cussing: 3rd place
• Added value: 5th place
• Local multiplayer support: 4th place
• Total score: 39 points

The Nazi zombie mode in this World War II shooter is one of the most lovingly presented historical recreations of a zombie apocalypse you can play. It's a reminder that even the greatest generation had to deal with its own zombie outbreaks. For added value, it's also got a middling World War II game attached.

2. Resident Evil 5

• Historical accuracy: 7th place
• Intensity: 7th place
• Tactical nuance: 1st place
• Gore and cussing: 4th place
• Added value: 1st place
• Local multiplayer support: 3rd place
• Total score: 43 points

There is no zombie killing game quite so cerebral as Resident Evil 5. Leave aside the issue of whether these are even zombies (I dinged its historical accuracy for that reason, as everyone knows zombies don't use guns). This is a great game not just because it's smart, but also because it's got so much else beyond co-operative zombie killing. If you take into account the versus mode (i.e. pay five bucks to download it), there are many variations on multiplayer gaming crossed with co-operative or competitive zombie killing. There are very few games that keep on giving so well as this one. I've played through it nearly three times and I'm nowhere near being done.

1. House of the Dead: Overkill

• Historical accuracy: 1st place
• Intensity: 4th place
• Tactical nuance: 10th place
• Gore and cussing: 1st place
• Added value: 2nd place
• Local multiplayer support: 1st place
• Total score: 47 points

And here you have indisputable mathematical proof that the best co-operative zombie killing game is also one of the best Wii games, one of the best light gun games, one of the best videogame soundtracks, and certainly one of the best stories about killing zombies. And even though the game insists these are mutants and not zombies, any amateur zombologist knows better. What Dawn of the Dead (the original, natch) is to zombie movies, House of the Dead: Overkill is to co-operative zombie killing: sloppy, over-the-top, profane, affectionate, keenly written, and timeless.