When you create a demonstration board from the new game window it can be edited immediately: useful for showing a problem or setting up an example game. Other players can watch, and you can let others edit the board as well. The other way to make a demonstration game is after playing a normal game you can review it by clicking Options | Review Game. This will make a new demonstration game intialized to the final board position in which you, your opponent, and other observers can play and discuss variations. The orignal game will remain in your game list unaltered. For more information on KGS's extensive reviewing features see Reviewing.
Teaching (T)
In a teaching game, the player playing white has the ability to stop the game, make some annotations or try out a variation, and restart it. A teaching game may be helpful when a strong player is playing against a weaker one. See the editing help page for more information. Unlike other game types, in a teaching game, players can see comments that observers make about the game while it progresses. A teaching game has no effect on ratings.
In a Simul game a player accept challenges from multiple opponents simultaneously. This is one of two special game types on kgs.
Rengo (2)
Rengo is the other special game type available on kgs. This game is special in that there are four players instead of two. Two players are assigned to each color (two for black, and two for white) The players alternate their turns accordingly. (first black player, first white player, second black player and second white player). Comments from observers cannot be seen by the players.
Free (F)
A free game has no effect on ratings. A free game is appropriate for casual play between rated players, and for play of rated players against guests and non-rated players. As with rated games, the players cannot see comments made by observers until the game is concluded.
Rated (R)
A rated game counts towards players' ratings. Both players must be registered players, the game must be on a 19×19 board, and with a handicap of six stones or less. In both rated and free games, players cannot edit the game until it has ended, and players cannot see comments made by observers.