So Besiege has finally announced and released the Multiverse Update, which is a multiplayer sandbox/Level editor and playable mode.
https://www.youtube.com/watch?v=Dh_LXRF0myw
Incredibly relevant to our interests is 0:20 to 0:35.
yes it has, in fact, me and some people in the OOTA discord have been experimenting with robot combat in it yesterday, we have came up thus far with a simple list of rules which seem to work decently enough:
-No explosives, unthetered projectiles or any fire based weapons.
-5 categories for block max limits
25 : FW
50 : LW
75 : MW
100 : HW
200 : SHW
-Robot must fit in the bounding box
-weapon spam bots will be banned
-bots cannot be fully assembled with ballasts or pistons
-grabbers are legal but you can only grab a robot for 10 seconds
-saws are banned
for now it seems to function decently enough, also with the way the engine makes every part fairly fragile it's very difficult to make an effective spinner that doesn't explode Apex style after a couple impacts, which can allow for pretty interesting designs.
i feel like that the uber-fragility of the game's engine is part of the challenge here tbh, also, braces say hello anyway
as for saws, at max speed they can cause a LOT of damage very quickly
and in fairness the grabber rule is more so clamps aren't a huge pain in the ass to make