Riot Games has introduced a new feature for League of Legends in which players may select a favorite type of role and be directed to a game where they can play in that role, much like, say, Healers LFG'ing in World of Warcraft.
According to the developer, "Team Builder is all about introducing a new, cooperative Champion Select where players can agree to a strategy and team vision before entering a match. Players in Team Builder will be able to outline a strategy they are interested in playing, and the system will find teammates that share that vision. Feel like playing a double jungler strategy or want to send 5 players down the mid-lane? No problem. It might take longer to find 4 other players willing to try a crazy strategy but when you do, you'll know the entire team is bought in and you're going to have fun."
Riot also thinks that this will be a good way for players to hone their skills in unfamiliar roles in live fire, but put them in games where their inexperience, even for veteran players, won't hurt the game. "First time playing Ahri? Learning how to be a solid Marksman? Venturing into the jungle for the first time? Team Builder’s matchmaking will take all of these factors into account," states the studio.
Check out Riot's full forum post on Team Builder.