The last time the rules for the challenge system were posted was November last year. They're on this thread, page 2, #38, but I'll just paste again here:
Players can challenge the champion with the following conditions:
a) They must have at least one "level 2" win. This means they have won at least one game against an opponent who also has a win.
b) If a player previously played the champion but lost, he can challenge the champion only if his score has improved since his game against the champion.
c) If there are multiple qualifying contenders, the player with the highest score can challenge the champion. If this player is idle (not in a game) and does not challenge the champion within 7 days, then the qualifying contender with the next highest score can challenge the champion.
d) A tie in score is broken first by judging the scores of player's opponent, and then by the number of games won as Black.
A champion normally plays White (unless he requests Black), and can choose the game to be played (any of the four Bulldog games). A champion that does not accept a challenge and begins play within two-weeks forfeits the crown.
Also note that the bulldog champion is allowed a "two-week rest" between championship games, and is allowed to finish any active games before starting a championship-level game.
However:
These rules will have some significant revisions prior to the completion of the next challenge game (which starts tomorrow in Junebug444 vs. Martin0).
I don't know the specific amendments yet, but the champ will get more "protection" from the larger number of players who are now playing. One possible change is if you challenge and lose, then challenging again will be made even more difficult.
I might also make a stronger definition for what qualifies as a bulldog game. Currently only this has been stated previously:
Bulldog games are played on a 10x8 board, and usually have one or two different pieces compared to classical chess. Games do not aim to be wildly different simply to be exotic or strange. Some consistency is desired so that concepts of strategy can be developed, without everything becoming obsolete with each new variation. On the other hand games intend to be different enough so that new territory is explored, and the games being played are not programmed in engines or stored in databases.
Other ideas are welcome. Just post here. But too many ideas can be hard to keep track of, and I'm trying to keep everything simple and fair at the same time.
@Waredude, you have never beaten me in any of these variants. What are you talking about?