Quake

id Software moved everything into 3D at once: levels, enemies and objects are built from polygons. There are no more flat pictures turned toward the player. Things Doom didn't have appeared: floors lie one above another, surfaces run at an angle, the view goes up and down, and the mouse goes from an optional convenience to the main aiming device. The price was the load on the machine: so that a frame can be computed in time, the lighting is precalculated and written into the map itself, and visibility between parts of a level is computed when the level is compiled.

No less went into networking. The game runs on a client and server scheme over TCP/IP, which means a match is put together over the internet, without a direct modem call; a separate update, QuakeWorld, rewrote the network code for slow lines. The rules are taken out of the engine into a separate language, QuakeC, so the behavior of a weapon or a victory condition can be changed without editing the engine itself. Out of this grew mods, clan tournaments and the occupation of server host. The engine's source code was later opened, and outside projects went on living on it for years.