All the advantages offered to the player character can make the game pretty easy, and in my opinion a challenging game is a fun game. Some players impose restrictions on themselves to make the games more of a challenge, level the playing field and make the competition seem more fair, or emulate the battle rules of the anime. After all, you never see Ash spamming Revives against a tough opponent!
These are my rules, or as I call it, my battling code. Most of them pertain to fighting bosses, such as Gym Leaders, Elite Four or evil team leaders.
-Only use the same number of Pokemon as the boss, and none of them are allowed to be at a higher level than their strongest Pokemon.
-You are only allowed to use the same number and type of healing items as the boss. This means no Revives!
-Pokemon that are considered overpowered for a point in the game (such as Scyther early in HGSS) cannot be used until you reach a point in the game where they would no longer be considered overpowered.
-Legendaries are not allowed to be used in the main story.
-All main team members must be caught in a regular Poke Ball.
So what rules do you follow, if any?