Well, since you’re reading this, it definitely means you’re interested in participating in Free-For-Alls with unovaunion! So here are the rules, just to make sure everyone has a fair chance.
Banned Pokémon. Arceus, Darkrai, Dialga, Genesect, Giratina, Groudon Ho-Oh, Kyogre, White Kyurem, Landorus, Lugia, Mewtwo, Palkia, Rayquaza, Reshiram, Shaymin-Sky, Xerneas, Yveltal, Zekrom.
Recovery Clause. You cannot have more than one Pokémon (out of the three Pokémon you choose during Team Preview) that knows a move solely for recovering HP.
Evasion Clause. Double Team and Minimize are banned.
OHKO Clause. Any OHKO moves are banned.
Moody Clause. The ability Moody is banned.
The Prankster ability and the move Swagger cannot be used in the same set.
If two or more Pokémon faint at once, the winner is decided by who faints last. In the case of Explosion or Self-Destruct, the Pokémon that used it is the winner.
The ability Telepathy is banned.
Also, be aware that defeating all Pokémon on the other side of the field will end the Free-For-All. (We wish it didn’t, but that’s game mechanics for you. FFA mode for Gen VII please?) Most often in those cases, the winner can be decided easily, but in cases where it is not obvious, it might be in your best interest to attack the player next to you to avoid ending the Free-For-All without a clear winner.