One-page games are good for /tg/ because their entire ruleset can fit into a single image. When printed, the whole game will fit on a single sheet of letter-sized (USA) or A4 (the rest of the world) paper without using stupid eyestrain-small fonts.
Almost every one-page game is free1 or Creative Commons licensed.
1: which is important since /tg/ would never scans books and hand out free copies. *cough*