Still sort of in the offseason, so I’ve got a fun mixer thread.
Think of one rule in past games that would have completely changed gameplay and outline some scenarios where it would effect things.
For example, descoring being legal in gateway.
Being able to lift/move the ladder in round up would have caused some trouble.
Not being able to throw objects out of the field in clean sweep.
These both would have definitely changed the finals of both of those competitions and maybe even would have affected the whole game play across the world
Being able to throw sacks out of play in Sack Attack. I would have loved that.
In sack attack balancing sacks on the field perimeter as a way to earn points would have been cool 
Not being allowed to put bases under the ladder or ram or block robots trying to hang in round up (similar to the rule this year in toss up). The first would have obviously changed the game (for the worse IMO), but the second would have been cool as it would encourage hanging designs more. Hanging was countered by ramming all too often, which is probably the reason for the rule this year.
Being allowed to enter an opponent’s isolation zone with the gate down in gateway.
Being allowed to use ten 393 motors in pre-sack attack seasons.
Only being allowed four 393s in sack attack.
Not a rule change, per se, but imagine if teams threw cubes out during Elevation. It was technically legal, but no one did it.
allowed to throw tubes out in round up
allowed to throw balls + barrels out in gateway
allowed to hold unlimited balls in toss up 
no repositioning in roundup 
They only didn’t do it because it was more practical to simply hold a bunch of them at once. Quite a few teams attempted this. However, at elite levels of play, a lot of scoring was done with autoloader cubes, and it was simply impractical to reach your opponent’s autoloaders before they did given the starting positions.
Autonomous programs would have been very different if the repositioning rules in gateway were more strict, like they were in sack attack. From my experience, most codes took advantage of only having to touch the starting tile, not be fully enclosed in it.
Gateway: Allowed to close and open the gate freely
Sack attack: The high goal can rotate around the post (as if it was not screwed in properly)
end up with lotsa crushed robots 
That happened once at the CSUN LA Regional during the quarterfinals, as seen here http://ecrchs404.shutterfly.com/11767#11768
Gateway: The gate must be operated by robots.
or the opponet can choose to open your gate anytime, but with their robot(s) only
Although I believe that they did lose to us in the match we played against them at the World Championship, one of team 40’s robots (http://youtu.be/WGQDfOErVTc) did this against us. It really surprised us, and we saw it as a brilliant strategy, leaving us with almost nothing to score halfway through the game.
~Jordan
Gateway: only being able to hold 3 pieces (or even more drastically 1 piece). We will see how it affects this year’s game.
Any game: Teams can intentionally detach mechanisms
round up hanging
thats our flag up there!
Teams can use two cortexes, do not need their robot to stay together, and are allowed up to 15 motors.
Heck, 12 motors would be amazing this year. Everything I go to build, I wish I was in college. That extra power would be so useful.