Is it possible to use OSM commercially?

I need some help..

I must admit that im not that strong on understanding licences or understanding when and where i can use which part in a closed source program that can be sold. Is it possible to use OSM in a program that does not alter its information but only uses it as a "playing ground" for a game?

Thanks and sorry for that (surely very dumb) question..

Phil (philipp.sorio(at)hotmail.com