SA2B Chibo and LK MM Rules:
Three Neutral Stages: Metal Harbor, Green Forest, City Escape
One person goes first and chooses a neutral stage (doesn't matter who). Player goes through the level as fast as possible trying to take as many shortcuts and score as much as possible. You are able to die one time, and if you do, you simply start back at whichever post you last hit (It's your choice throughout the level to hit them or not, but no restarts).
The next player plays the same stage and has to also play their best. Whoever has the shorter time wins.
The same repeats with the other person choosing the stage first (no stage can be played twice in a row).
If a tie breaker is needed, a third match will be played on Final Rush, letting each person die a maximum of three times. If somehow both players died 3 times, it will go onto the 4th match on the remaining neutral with the same rules as earlier. If both players die and are still tied, then the money match is null and void.
Modifiers: To mix things up, you can add challenges you can call after you are done playing level and before it is your opponents turn. You can only call modifiers on things that you did as well, sort of like they have to match your skill. Modifiers can include things such as: if the first player does not die, they can challenge the second player to do the level without dying at all (no playing safe intentionally, you still have to go for death defying shortcuts that are within reason), or to match your level rank (or do better), or something level specific such as make it to the top grab on the rocket at the end of Metal Harbor. Modifiers can not be used on Final Rush or the 4th match.
It's sort of confusing, but it makes sense lol