1.You are only allowed to recruit the Pokemon that wants to join you first in each dungeon. In the case of a Pokemon wanting to join you as part of the Spinda's Cafe drinking events, you can accept the first one. Same with Pokemon asking to join you via completing jobs
2.If a recruit faints, you must release it from the team. If a character dies that cannot be taken of the team(your partner, Grovyle, etc) you must sacrifice a recruit so you still get some penalty for fainting. (The following rules are optional variations you could add to make it harder)
3.Nickname all recruits
4.Ban the use of shops
5.Randomly choose your partner using sites like Random.org
6.Answer the quiz in a way that means you will get a Pokemon that makes the game a little bit more difficult(Skitty has real problems against Dusknor due to her ability, Fire types struggle with Palkia, ect)
7.You cannot change a member of your team for a recruited Pokemon unless a member of your team dies/is sacrificed.