HP-based effects
When calculating changes in HP (damage or restoration) based on the percentage of a Pokémon's maximum HP, the Dynamax Pokémon's non-Dynamax HP is used. For example:
Super Fang inflicts damage to a Dynamax Pokémon equal to 50% of its non-Dynamax HP.
A held Figy Berry will restore HP equal to 1/3 of the Dynamax Pokémon's non-Dynamax maximum HP.
Endeavor inflicts damage equal to the amount that the target's non-Dynamax HP exceeds the user's non-Dynamax HP.
Pain Split averages the two Pokémon's non-Dynamax HP, calculates the signed difference between that average and each Pokémon's non-Dynamax HP, then changes each Pokémon's HP by that signed difference.
Effects that vary based on the percentage of HP a Pokémon has remaining use the Dynamax Pokémon's Dynamax HP. For example:
Emergency Exit activates when the Dynamax Pokémon's current Dynamax HP falls to 50% or less of its maximum Dynamax HP.
A Pokémon will consume its held Figy Berry when its HP falls to 50% or less of its maximum Dynamax HP.
Brine's power is increased if a target Dynamax Pokémon's current Dynamax HP is 50% or less of its maximum Dynamax HP.
The moves Dynamax Cannon, Behemoth Blade, and Behemoth Bash do double damage against a Dynamax Pokémon.
Immunities
Dynamax Pokémon are immune to flinching. Fake Out can still damage a Dynamax Pokémon, but will have no secondary effect.
Dynamax Pokémon are unaffected by moves affected by weight (such as Low Kick and Heavy Slam), one-hit knockout moves, and Destiny Bond.
Moves and Abilities that replace the target's Ability with the user's (such as Skill Swap, Entrainment, and Wandering Spirit) have no effect on Dynamax Pokémon. However, moves that change or suppress the Dynamax Pokémon's Ability altogether (such as Gastro Acid and Worry Seed) still work.
Dynamax Pokémon cannot be switched out by the effects of moves that switch the target out (like Roar and Whirlwind). Circle Throw and Dragon Tail will still damage Dynamax Pokémon without switching it out. Red Card also fails to switch out a Dynamax Pokémon, but is still activated and consumed. Dynamax Pokémon can still be forced out by their own Abilities or items, such as Emergency Exit or an Eject Button. If a Dynamax Pokémon has Magic Bounce and is targeted by Parting Shot, the move will be reflected and force the Dynamax Pokémon to switch out (the owner of the Dynamax Pokémon is still able to choose the Pokémon that it is replaced with).
Dynamax Pokémon cannot be affected by Disable or Cursed Body. A Max Move or G-Max Move can still be used if its base move was disabled prior to Dynamax. Dynamax Pokémon are also immune to Encore, Torment, and Instruct. Choice Band, Choice Scarf, Choice Specs, Gorilla Tactics, and Sheer Force temporarily stop working (including the stat boosts) if the holder is Dynamaxed. However, Assault Vest still works accordingly and prevents the holder from using Max Guard.
In addition to the above, there are certain moves that will fail if used during a Max Raid Battle, but will work against a Dynamax Pokémon otherwise.
