In memorium

The flags are flying at half mast today at Valve as they commiserate the resignation of South Australian Attorney-General Michael Atkinson. Luckily for some, they are also flying the Attorney-General's greatest legacy at half-price: the gore free, censored Australian edition of Left4Dead 2. Even this cheap, I'm not tempted by the artistically dismembered version Valve have been forced to sell down under.

Momento mori, Mr Atkinson, momento mori.

Left4Dead Week: Failing is Fun

Left4Dead week will feature one short piece on Left4Dead each day this week to celebrate the full release of the game.

No other game celebrates the fun of failure like Left4Dead. (Except roguelikes. And Dwarf Fortress. Screw you Jonathan Blow for making failure impossible...) So it's time to second guess the designers and come up with some game 'improvements' to see if our hypothetical Left4Dead design can improve on the high standards set by the original.

And nothing says improving game play by adding stuff randomly without testing. So I'm going to suggest the addition of three more weapon types, and one more playable zombie. Ah... variety. The spice of life to cover up the stench of death.

Three additional weapons

These weapons are placed by the AI director - but instead of having a table from which you can pick 3 from, there's only a maximum of one per level, which comes with a fixed amount of ammunition which you can't refill. Think of these as a short term power up that one player gets to steal from everyone else. And fails with it.

The Chainsaw: How Valve released a zombie game without a featuring a chain saw beggars belief. Of course, they should really have included a lawnmower. But a chainsaw is close enough.

Primary fire: You saw through zombie flesh. It doesn't so much do damage, as carve up any regular zombie as soon as you hit it. Against special zombies, the shower of blood blocks your vision much as a Boomer's vomit does, but in a different colour.

Secondary fire: Melee attack like every other weapon which pushes zombies away. Occasionally your chainsaw will get stuck in a zombie while using primary fire and you'll have to clear it with the secondary fire.

How failing with it is fun: You'll notice that the primary fire doesn't push zombies away... so getting surrounded is just as bad as before. Plus: play a coop game, and take away someone's ability to use their primary weapon at range. Then see how everyone else feels.

Wait. Valve did that in Left4Dead with the Akimbo Assassin achievement. Nothing to see here then. Move along.

The Flamethrower: Lots of burning stuff. Check. Zombies on fire. Check. Ability to set zombies on fire using a flamethrower... didn't Valve watch the Thing?

Primary fire: Flame. Glorious flame. Watch how it burns. I'm waiting right now for a barbecue to get delivered. True story. I wonder what zombie flesh tastes like. I'm guess a chicken version of Spekekjøtt... mmm...

Secondary fire: Melee attack. Like everything else. Of course bashing the flaming end of a petrol tank against something hard is a low risk proposition. I wonder how often it'll blow up.

How failing with it is fun: Aside from the random petrol tank explosions - and how often have you accidentally shot a fuel canister in Left4Dead already without strapping one to your back and standing in front of your companions - the flamethrower doesn't have any stopping power. So instead of being rushed by zombies, you'll be rushed by zombies. On fire.

The RPG: Midtown USA features lots of military grade equipment. Like Russian made Rocket Propelled Grendade launchers. And General Purpose Machine Guns. I actually thought long and hard about suggesting a GPMG. Until I realised that you'd have to go prone to set it up. And as Counterstrike has shown, going prone just encourages tea bagging... can I point out that tea bagging an AI tank you've just taken down doesn't have quite the same emotional force as someone who is forced to watch you sit over them with the in-game camera? It's funny when someone tries it on a downed comrade in Left4Dead. Because your dual pistols beats their dual... no wait. Lets not go there with this analogy.

Primary fire: Great for busting tanks. And fixed emplacements. Except most tanks move reasonably slowly and you can get at the weak armour from behind. Not charge at you throwing chunks of concrete while on fire (if you're lucky).

Secondary fire: Me... I think you can guess by now.

How failure is fun: Slow loading weapon. Fast moving zombies. Hmmm...

One additional playable special zombie

I didn't quite intend this article to end up as a humour piece. How the best laid plans go awry. But that's what we're talking about here.

One of the best laid plans in Left4Dead is to hole up somewhere while you're getting rushed. If you've got good line of fire and disciplined players you can hold off the regular zombies, push Boomers and melee release your colleagues who get caught by Smokers. Ideally your position shouldn't even be accessible to the special zombies because you've closed the doors leading to it.

So that's what this zombie type does. Force you to move...

The Swarmer

Picture the Candyman. But with flies crawling out his eyeless sockets instead of bees. And pale, decayed flesh, with red raw scars. And no hook. Maybe just the stump of a hand. But you get the idea.

Primary Attack: Melee attacks. Roughly boomer strength. This guy wants to get reasonably close to the enemies. Not boomer close. But faster moving.

Secondary Attack: Fly strike.

The fly strike spits a decayed lump of flesh surrounded by a swarm of flies at slightly further a distance than Boomer vomit. The location the fly strike hits is immediately filled with a cloud of flies which lasts, say, 15 seconds. This has no initial impact, but if any survivor stays within the cloud of flies for more, say, than 5 seconds, they are affected by a denser swarm of flies.

The swarm of flies effect causes the survivor to continuously lose health until either they become incapacitated, or have another survivor remove the swarm of flies effect, using the E key for a short duration.

Fatality: Killing the Swarmer releases a cloud of flies, with the same impact as their secondary attack. (Maybe this guy plays too much like a Boomer).

Sounds: The Swarmer is identified by the sound of the buzzing of flies around it. A intense, angry buzzing as if drawn to a putrid corpse...

Mmm...

Left4Dead Week: The Befriendening

Left4Dead week will feature one short piece on Left4Dead each day this week to celebrate the full release of the game.

Several other bloggers, who shall remain nameless, are delaying playing Left4Dead until they can find some friends to play through with. The call for friends is pretty wide: if you've read any of these blogs, you'll see that they're asking for game tags in the comments post so that they can add their readers to their Steam or Xbox accounts.

I'd suggest that Left4Dead is best played with anonymous strangers. Not because griefing is fun, but because the game's cooperative mechanics brings out the best in people. You must keep everyone alive or you die. Horribly. And I've never had so many Steam friend requests as I have had with people I've played Left4Dead with.

(That's not to say I don't seem to end up taking the brunt of zombie abuse. I've yet to finish a 'movie' - a map sequence in Left4Dead parlance - without being killed between 6-10 seconds before rescue turns up. And everyone else getting away... for the greater good. If not achievements).

Left4Dead Week: The AI Director – Part Three – The Rise and Fall

Left4Dead week will feature one short piece on Left4Dead each day this week to celebrate the full release of the game.

A number of reviews have highlighted the sophistication of the spawn system, so that you never see the director spawning zombies directly - they always appear off screen and then rush you.

What reviewers don't seem to have mentioned as frequently is the way the level design aids and abets this. If you're in a wide open area, you can be sure the zombies will be clambering over a nearby fence, crashing through windows or running over a rooftop. And in enclosed areas, you'll find holes in the ceiling from which they'll pour. The most elegantly designed area for this is the start of the first map for No Mercy, which features in the demo.

An in a post 9/11 world, Valve can't be ignorant of the significance of watching bodies falling through space.

(No Mercy has the best opening area of any of the first maps. For the best opening sequence of a final map, you'll need to play through Dead Air. At which point one of my fellow players yelled Game Over man, Game Over! the second time we watched it through.)

Left4Dead Week: An Open Question for the former Turtle Rock Studios

Left4Dead week will feature one short piece on Left4Dead each day this week to celebrate the full release of the game.

I see Left4Dead has inherited what I like to think of as the ‘grenade problem’. What I mean by this is that the investment required to get the AI to use grenades correctly is too high to justify; and unlike many other AI problems, an intermediate implementation (that is getting the AI to pickup and throw grenades badly) is worse than no implementation at all.

Ironically, the friendly AI bots in Counter Strike seem to use grenades reasonably well, and Turtle Rock Studios implemented this as well. So I was wondering what the issue behind not doing the same in Left4Dead was? And I suspect it is a simple return on investment problem. Left4Dead is intended as a coop game and friendly AI using grenades was well down the list.

(Other than that, great job guys).

[Edit: Robin has suggested an interesting alternative in the comments].

Left4Dead Week: The AI Director – Part Two – The Zombies

Left4Dead week will feature one short piece on Left4Dead each day this week to celebrate the full release of the game.

The problem with the AI director is that I think the implementation works too well for zombies, and won’t be adaptable enough for anything else. The quiet, eerie moments of being unsure whether an area will be filled with mindless undead, crouched shivering in a corner, leaning helplessly against a wall or vomiting up raw chunks of flesh, or completely empty; the variation in threats from rushing hordes, against the lesser special zombies (boomer, smoker or hunter), the adrenal rush of fighting a tank or trying to creep past a witch.

Contrast this with Half-Life 2, where there is a similar variety in enemies, but all of which are pre-figured by the environment you are moving through: no mix of head crabs, combine and Ant Lions together would make as much sense. And the simplicity of the zombie AI will make it hard to have a similar flood, of say, Nazis en mass. Any more intelligence in the enemies than that which the zombies display would dilute the flood to a surge or trickle, as they found alternate routes, held back or hid within the level to wait for you. The techniques used by the ALife in S.T.A.L.K.E.R. makes more sense for the most games: where each enemy has a distinct personality and set of goals to move through large free roaming levels.

Left4Dead Week: The AI Director – Part One – The Musical

Left4Dead week will feature one short piece on Left4Dead each day this week to celebrate the full release of the game.

The AI director works well, especially in conjunction with the musical cues which are used to tell you when you are about to be swarmed with undead en mass. I suspect some of these cues will become repetitive over time – it would be good to mix them up a little with sound cues for the same effect (such as the sound of zombies crashing through a wall, or baying for blood in the distance). I also missed the sound of other people fighting the zombie apocalypse: surely the four survivors can’t be the only people trying to escape the city. The Miles Sound system API in Source works well for this as demonstrated by the sound of gunfire in the distance in Day of Defeat or Half-Life 2.

Left4Dead Week: Destructible Scenery

Left4Dead week will feature one short piece on Left4Dead each day this week to celebrate the full release of the game.

Left4Dead has a reasonably robust implementation of destructible scenery, without reaching the flexibility of Fracture or Red Faction. Elements of the level, notably windows, doors and some walls can be destroyed; mostly by the marauding undead who feature in the game. There’s several nice features of the way Valve has implemented this:

1. There’s no obvious seaming of destructible elements, or any other indicator to differentiate destructible or non-destructible. This means you can never be sure if a wall will be torn asunder as a zombie crashes through it. Some walls do get destroyed too frequently to be a surprise: such as the wall below the collapsed room in the apartments; but I bet you didn’t know that one of the upstairs room walls can similarly be blown apart by a Hunter coming down from the roof.

2. Closed doors block the undead from moving through them - instead they start to bash chunks out of the door in horror movie cliché style. This can be used tactically, such as to hold up a flood of zombies while you shoot them apart.

3. The tank can tear up chunks of concrete and throw them at you. These chunks don’t have any long term effects, but it sure looks good.

4. The fragments of the destroyed scenery end up as physics elements which can be pushed around further, such as when a boomer or pipe bomb explodes.

5. You’re not forced to progress through any destructible scenery yourself: there’s always a route around. This means you don’t have to figure out which part of the map the level designer was hinting you should blow up.