Tetris is NP-Hard

I stumbled apon a very fun paper the other day.

Just reading the abstract alone made me smile a few times. The paper itself is super theoretical, but because I've taken a few courses in complexity theory, I was able to appreciate it nonetheless. It also turned out there is a small field of reasearch on the complexity of Tetris just from looking at the references. The main contribution of this paper is to show that Tetris is NP-Hard even for cases where you don't assume much of the board size.

There's also really cool latex tricks being pulled off in this thing. All across the paper you can find these little refences to tetris shapes.

But the coolest thing is the final sentence in the abstract. The authors actually took the effort to add a section in the paper the shows a custom font made out of tetris shapes. As it turns out, each 8-row letter can be made by stacking each of the seven shapes exactly once in an order that actually can be created during a tetris game.