New rule. I call it the “Gary Oak Is a Motherfucker” rule.
The problem with Gary (and Pokérivals in general) is that a) they are very high level compared to other trainers you’ve dealt with leading up to that fight, and therefore will obliterate you if you aren’t ready for them, and b) they appear out of nowhere, so you WON’T be ready for them, unless you’ve played through the game before and know when to expect them.
(Yes, it is obvious at this point: Gary kicked my goddamn ass in Cerulean.)
It is not really suggested that you play your first run through a pokémon game this way. But I want it to be possible, so something obviously needs to be done about that motherfucker Gary.
The Gary Oak Is a Motherfucker rule is this: For any trainer battle in which the trainer surprises you by running in from offscreen, you are allowed one mulligan — that is, any pokémon fainted in your first attempt only at that fight may be healed for free, without revives, even in the event of a total party wipe. If you wipe, you had better find somewhere else to train before activating that event again.
If you know when and where Gary shows up, you may not take the mulligan. This is only for unexpected trainer battles. (And, to reiterate, they have to come from offscreen, so “I didn’t know that NPC standing there was a trainer” doesn’t count either.)