- College coin toss rule. (Whichever team wins the coin toss can elect to play offense first, play defense first or which end of the field the first round takes place in.)
- No game clock (Play clock is still there, 4th quarter rules)
- Offense starts at the defense's 15, 1st and 10.
- If a team scores a touchdown they may
-> Attempt an extra point from 55 yards AND
-> Attempt a two-point conversion at their opponent's 3 yard line.
- Whichever team either ends the round with more points than their opponent, or scores more points than their opponent is able with their remaining attempts wins.
Repeat if necessary until someone wins.
Each of the items I chose, the coin toss, starting at the 15, 55 yard FG and 2pt at the 3 are all about 50/50 odds of success (or as close as my limited research could find to it) so overtime would be as fair as possible, but by stacking multiple 50/50 odds on top of one another you make it far less likely both teams will end up with the same result, thus keeping overtime short, sweet and decisive the vast majority of the time.