The USS Quad Damage

Tetris is NP-Hard

Have you ever noticed that after playing a tetris-like game (any game involving the sorting and placing of blocks), your brain ends up being completely fucked up?

I'm currently speaking of "Crack Attack!" on Linux (similar to tetris attack), but I've also had the feeling with Columns, and of course, Tetris. The feeling is like this: after having played a game which consists entirely of composing blocks, you start picturing life as a block-composing exercise.

The first time this happened was with "Columns". For those of you who don't know, Columns (sometimes named "Jewels" or "Bejeweled" or some knockoff of that name) is a game where you get 3 square blocks of different colours, vertically arranged, coming from the top, ala tetris, and you re-arrange (the colours on the blocks, not the orientation) and place them. When you get 3 or more in a row (across, vertical, or diagonal), they disappear. The interesting thing then is that the blocks above them (if any) fall down. If the fallen blocks create another 3 or more in a row, they disappear too.

The trick is not to get just 3 blocks disappearing, but to get 4 or 5 disappearing, then setting off a cascade of whole chunks of blocks disappearing (a "chain" or a "combo"). This link is to the popcap version of the game, which is heavily modified (the only similarity being that the blocks fall and the combos), but it gives you an idea.

There are subtle timing issues as well, like when you match a set, the game will wait a bit so you can set up your next move, but anyway, what ends up happening in the real version of the game is that you start setting up your blocks not so that they match, but so that they slightly don't match, because that way they'll be involved in a chain when you finally match something. First you're setting up simple chains, and eventually you've got cascades the likes of which the scientists in half life would be proud to set off.

And it twists your brain, big time.

I was playing this for close to 5 hours one time. Afterwards, Everything I saw, I automatically arranged into slightly off patterns, patterns which would eventually give me many points in the game, but really meant nothing in real life. Whelther it was tiles, objects, anything. Like nathan's sorting algorithm, I couldn't help but do it constantly. Before going to sleep that night, I was staring at the wall, and I swear I saw jewels, arranged in a pattern, and I found a brilliant strategy for increasing my cascade lengths.

Tetris, I don't need to explain. If you don't know about Tetris, you shouldn't be reading this. Go and die, you fucking lunatic. Anyhow, Tetris is another game that does this mind alteration, but it's a lot milder. I don't know if you've seen the simpsons episode where homer arranges the members of his family in the car ala tetris, but it's sort of like that. If you've ever looked at clothes and marvelled at how they fold and shit, you know what I'm talking about. It's a sort of a wierd dread at the same time, though. Your brain says "these things are, like, flexible... I have no fucking idea how to arrange these objects." Another symptom is the disappearing line. When you arrange objects, you expect them to magically disappear, and when they don't, it takes a few seconds to work out why.

Crack attack is another game (based on Tetris attack, and similar to that medicine game, I forgot what it's called but it's a great game) that screws up your head. Basically, rows of different coloured blocks rise up from the bottom. You swap these horizontally, and the game works like Columns (except no diagonals). On top of that, though, these slabs fall from above. The slabs aren't coloured blocks, they just get in the way. To get the slabs out of the way, you have to match a set of blocks adjacent to a slab, and the slab turns into a set of blocks, which you can then deal with. When you hit the ceiling, the game is over. This game also has subtle timing issues, like the waiting after a match, and a bit of time when the blocks hit the ceiling.

The thing with this game is the pace. The game quickly increases in speed, and you have to work frantically to match blocks. There is a genuine fear of hitting the ceiling, because when you do, you've got to work real hard to not lose. It's edge of your seat. I played this for maybe 15 minutes today. When I stopped, I started up my web browser. As I scrolled down the page I felt a startling fear grip me, and I thought "Oh shit, the blocks are gonna touch the ceiling soon. I better get my act together."

And that's why I wrote this article.