This weekend GOG.com's giving everyone a chance to complete their Gabriel Knight collection - one of the best adventure games series ever created! Until Monday, May 24 at 11:59 p.m. EDT (Tuesday, May 25 at 5:59 a.m. CET) you can grab those classics with a 30% discount if you buy all three parts of the series or if you complete your collection of GK games in one order - that's less than $13 for all 3 games. If you buy the games individually you'll receive a 15% discount. 

With the promo GOG.com is also lunching a Twitter contest. If you have a Twitter account just retweet this message: "Complete Gabriel Knight collection for less than $13 http://bit.ly/cfy0wq #gog" and you'll automatically take part in a lottery for 1 of 5 codes for free GOG game.