Scribe is a free pen-and-paper game that needs a printer, but then you can play it right away. The game setup is randomly generated, so you get different maps every time. It usually takes about minutes for 2 or 4 players.
Rules PDF, download and print it out once
Village page, print one for each player.
Two player page, print one for a (2 player) game.
Four player page, print one for a (4 player) game. (untested)