Battle for Wesnoth
Battle for Wesnoth, or BfW for short, is a popular turn-based strategy game which takes place in a fantasy universe and has support for singleplayer and multiplayer, official campaigns (and more available to download), hotseat games. The game comes by default with 6 factions and takes place over hexagons, each player deploying his army and trying to kill his opponent. Wesnoth can be highly modded via WML (Wesnoth Markup Language), and the add-ons server includes many more maps, factions, eras and campaigns. Beside for the usual mode which allows up to 9 players to battle against each other or forming teams, there are also the rumble maps (very small maps), or the survival ones, or the multiplayer campaigns or role playing maps. There is also an unofficial ladder available. Wesnoth is really an awesome, complete game, with a great community, great online playing, music themes, map editor, a great helping system, and much, much more.

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Xonotic is a free first-person shooter game for Linux, Windows and Mac OS X. The Xonotic project started as a fork of Nexuiz, a game which was popular for many years on Linux. The fork was created because Nexuiz was licensed to IllFonic game studios, and it is to be used as a platform for developing a commercial game for Steam, Xbox and PlayStation.

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