I'm in a Roto Ultra league (the updated rules used by the first roto league with Daniel Okrent and the lot). There are other twists, but basically, any player won at auction is signed to a three year contract at the salary he was won at. You can get rid of players via waivers or trades, where the player's new team would pick up the remainder of his salary. Otherwise, there is an acutal monetary penalty paid into the league's prize pool for getting rid of a player before their contract is up. Teams can also sign players to extentions inbetween the second and third year of their contract, up to three extra years with a salary increase of $5 per extention year.