In Canadian football, you get one point for MISSING a field goal as long as it has enough distance to land past the end zone.
Ultimate frisbee is self-officiating, as in the players call fouls, travels, etc. Then the player they called it on can contest the call or not, leading to a lot of arguments on the field.
The driver who gets the most mentions on Twitter during a race gets to use extra power (it’s electric Formula racing, so they can do that in software for some amount of time).
In hockey if you high stick it’s a two minute penalty, but if you make the person bleed it’s an extra two minutes.
In USAG club Gymnastics, your sports bra and panties must be either nude or the color of your competition leotard, or else you get a couple tenths off your score.
In Australia, if the grand final game is tied at full time they come back and play it all over again the following week. Overtime isn’t an option.
Golfers have to sign their scorecard and if there’s a mistake they are disqualified, even though their score is being kept by others for the entire duration of the game.
In chess there is a rule that a woman has lost a game if she has too much cleavage showing. If her opponent claims this happens, there is a jury who will decide whether the woman has too much cleavage showing or not.
In the NFL, if you fumble the ball in the opponent’s endzone and it goes out-of-bounds, it’s their ball on the 20 yard line. If you fumble the ball on the one yard line and it goes out-of-bounds, it’s still your ball on the one yard line.
In hockey, if a player hits the puck and it goes over the glass without touching anything, it’s a two minute penalty. But, if the puck clears the glass after touching the glass, there is no penalty.
In golf, you can be watching on TV, call in, and point out a rules violation, thereby getting the golfer disqualified.
In water polo, if you block a shot out of bounds, your team gets the ball, the opposite of almost every ball-centric sports.
Catching the snitch grants 150 points. What’s the point of even trying to score if you get so many points for the snitch?