Mega Evolution

In this RPG, we allow any fully-evolved Pokémon to mega evolve, ensuring the Pokémon you like can have a mega evolution. The player and the GM work to figure out what that mega evolution would look like.

Mega evolving is a free action. You must own a key stone and your active Pokémon must be carrying the proper mega stone.

You can only use your mega stone to mega evolve one Pokémon once per scene, and doing so costs a kudo. Unlike thunder stones or fire stones, mega stones are not consumed and the Pokémon reverts to its normal form after the scene or fight is over.

Suggested Mega Evolutions
Here are some ideas for mega evolutions.

Default
A general way of handling mega evolution is to increase the Pokemon's max HP and current HP by 100, and have all its moves become natural. The mega form may have a different type or ability than the standard Pokemon. If the Pokemon gains the gargantuan ability as part of its mega evolution, the bonus 100 HP are added after multiplying the Pokemon's HP by the gargantuan multiplier.

You may be tempted to do an increase in stats, but we've found that this produces an unneeded complexity, requiring recalculation of natural moves, range, dash, HP, and so on. You may choose to add a second ability on top of the normal one, and the Pokemon only gains 60 bonus HP, or it may even gain 2 extra abilities but not bonus HP.

Kangaskhan
For this Pokemon, Kangaskhan actually gets no more powerful. Instead, the youngster in its pouch does, able to hold its own in a fight and immediately is placed on the space adjacent to mama. Junior has all the same moves and stats as its parent, with the exception that it starts with 100/100 HP. Both of them may take a dash action, and either of them may take a command action. If both of them can carry out the same command action, such as using an attack against the same target or using a self move, they may do so. Both junior and the parent need to be fainted before the pair is taken out of commission, and having both on the field bypasses the normal one Pokemon at a time rules. They track burnt out moves, HP, and statuses separately.