Not the old-fashioned kind, in which the champion kept the title by drawing the match. That has been abandoned since it would be a huge advantage with matches as short as they have become. hansie bring this idea in the comments:
In the event of any world championship match ending at tie, 6-6, after the regulation 12 games at classical time control, what do you feel of replacing the rapid cum blitz tiebreaker by a single armageddon (13th) game at classical time control with the Champion having the Black pieces and the Challenger having the White, with the proviso that the Challenger must win the game to dethrone the Champion, if the game ends in a draw, the Champion keeps his title on the ground that he could not be defeated in the match despite having more Blacks and less Whites?
My very first instinct was to hate it. But my second reaction is that it's no worse than rapids and blitz and has a cute logic. Another 60 seconds in and I'm almost in love with it. Has this idea been postulated before? Seems too good not to have been.
The main downside is if the champion loses the draw odds part is forgotten and there's a beef about color disparity. If he draws it feels fair, but if he loses it looks odd. Draw odds games are a pretty serious distortion, basically. Same goes with time handicaps, etc. Any time you have to asterisk a game -- that is, it wasn't played under normal rules -- you're playing with history and with fire. Still, while my traditionalist side rebels it's certainly a tidy idea and one I'd like to see run by players for fun. Most feel draw odds are such an advantage that they might think this is too much to give to the champion. See our recent US championship threads on the armageddon time handicap game system they used this year.