I know it's off-topic, but... can someone explain this to me? People say this all the time, but everyone just assumes people will take that for granted and no one ever elaborates on what they mean.
As a mechanics researcher myself who very strongly emphasizes cartridge accuracy, I feel like I can offer some insight on how
National Dex mechanics work and their consistency with cartridge play. I'll just address the mechanics that would be relevant in Doubles OU.
1) All past Pokemon are returning. This does not mean unreleased Pokemon (like Floette-E, or unreleased Gigantamax forms like Toxtricity's), but any Pokemon that was playable in standard Smogon Gen 7 formats. This also only applies to Gen 7 Pokemon, not past gen Pokemon like Cosplay Pikachu forms.
The ultimate decision of this is fairly irrelevant to the metagame as pastgen exclusive Pokemon and unreleased formes would generally not be good anyways. I think it's fair enough to say that because Totem Pokemon cannot be placed into Pokemon Bank, Game Freak pretty well ruled out in advance the idea of Totem Pokemon continuing to exist in Generation 8. I'd prefer this rule be stated and enforced with respect to "what can be put in Pokemon Bank" but it's moot.
2) Mega Pokemon and Primals are returning and will be usable. The mega restriction still applies (only once per battle, same as Dynamax).
One unanswered question is with regards to the interaction of Mega Evolving and Dynamaxing on the same turn with a different Pokemon - is the order in which they Mega or Dynamax determined by Speed? Does one always happen before the other? We're also making the assumption here all Mega stones are released (which wasn't the case in early SM for example), but I think that's fine given you're assuming Mega Evolution is possible.
3) None of these additional Pokemon will receive updated movesets. Even if it's likely Garchomp would be compatible with the Dragon Dance TR, that's not happening.
This makes sense generally speaking. You really have no idea what new Egg moves or TM moves a Pokemon would receive, and rather than arbitrarily decide which Pokemon "should" receive Egg and TM moves you just ignore the lists altogether.
4) If you have a mega stone, z-crystal, or primal orb on a Pokemon on your team, that Pokemon will not be able to Dynamax or Gigantamax. This restriction, however, will not impact the rest of your team, so you can use one z-move, mega evolve one Pokemon, and dynamax or gigantamax one Pokemon per battle.
Awful wording, but this is just saying you can't Dynamax a Pokemon holding a Mega Stone or Z-crystal. The "precedence" here is Rayquaza in Generation 7 being unable to both Mega Evolve and use a Z-move; if it was holding a Z-crystal, it would could only Z-move, never Mega Evolve, even if another mon used the Z-crystal. So the
most current generation's mechanics are prioritized in the move selection screen, so the interaction in National Dex is against precedence. Of course, since pretty much
every Pokemon can Dynamax you have to break that rule or else nothing could Z-move or Mega. But then it seems to me that being unable to Dynamax a Mega, or being unable to Dynamax a Z-crystal user is just
arbitrary. Why can't I Dynamax my Kartana, get +1 Speed from Max Aerial Ace and set Grassy Terrain with Max Leaf Blade, then Z-Leaf Blade after my Dynamax ends? The real reason is because of
balance, not because of any precedent. If anything, precedent is to
allow Z-moves after a transformation. Ultra Necrozma is our best Gen 7 example of this - first you Ultra Burst, then you can Z-move, which replaces the previous Ultra Burst option. Why wouldn't Dynamax and Z-moves be the same?
5) No new moves added in gen 8 can be used for Z-moves. Behemoth Blade or Drum beating simply won't be compatible with Z-moves.
Sure, why not. This is the same logic as TRs and Egg moves; there's simply no data of what "Z-Behemoth Blade" means.
6) All moves are returning as well, meaning you'll have access to the moves cut out of Sword and Shield. They also do have max moves based on the regular max move formula (i.e. Pursuit turns into 90 BP Max Darkness).
This might come as a surprise to players, but Max Move BP of snapped moves exists. Return and Frustration, for example, are coded to have 130 base power as max moves, and Hidden Power follows the normal scale and will become 110 BP despite being potentially Fighting-type. So the second half of this actually isn't a National Dex mechanic.
8) Old items are being brought up to complete these mechanics changes (mega stones, etc.), as well as unique held items for Pokemon that were not included in Sword and Shield. The full list is: All Z-Crystals, Mega Stones, Arceus Plates (except Pixie Plate which is already in the game), and Genesect Drives, Blue Orb, Red Orb, Deep Sea Scale, Deep Sea Tooth, Lucky Punch, Soul Dew, Thick Club, Lustrous Orb, Adamant Orb, Griseous Orb.
This seems ok to me if you assume a Pokemon Bank-style restriction as I outlined in 1). You can't transfer items, so you can't transfer Rowap Berry when it's unable in SwSh. But then I see absolutely
no reason why items like Soul Dew, Thick Club, or Deep Sea Scale are allowed; these aren't transformation items, and they don't relate to Mega Evolution or Z-crystals at all. It's just
arbitrary that these items happen to be allowed and things like Custap Berry or Razor Claw aren't.
9) Generation 8 Pokemon can't learn moves that were removed in Sword and Shield since they aren't in their natural movesets. That includes formerly universal TMs like Hidden Power.
This makes complete sense.
12) If Ditto transforms into a Pokemon that cannot Dynamax, it will not be able to Dynamax. That includes Mega and Primal Pokemon, Ultra Necrozma, Zacian, Zamazenta, and Eternatus.
Can Ditto not Dynamax if it Transforms into a Pokemon holding a Z-crystal? Surely not, right? Can Ditto Dynamax if it Transforms into a Pokemon pre-Mega? I get the precedence here with Zacian and co. but this is very poorly worded.
13) Forecast will not transform Castform into its Sunny or Rainy forms if it's holding a Utility Umbrella, and if a Utility Umbrella is tricked onto Castform's Sunny or Rainy form, it will transform back to its base form. Since Utility Umbrella does not protect from Hail damage or effects, this does not apply to Castform's Snowy form.
An arbitrary distinction that as Hematite says, is largely irrelevant.
14) The max moves of Hidden Power and Judgment change type to be the type their non-max move variants have been set to be. For example, Arceus-Normal's Judgment becomes Max Strike, but its Hidden Power Fire would be Max Flare. This is because Multi Attack, which is actually in Sword and Shield, changes max move type in this manner.
I think from a mechanic perspective this makes perfect sense, as stated with Multi-Attack. However, from a competitive perspective, I think it's a nightmare. Giving nearly every Pokemon in the game access to Hidden Power is too strong for Dynamax I think, because it means every Pokemon gets Max Airstream. Imagine a Xurkitree, which sets up Tail Glow and proceeds to Max Flying and Max Electric, gaining Beast Boosts along the way. You can think of any number of absurd comboes in having access to an arbitrary max move of your choice.
Here's just a short list of questions I thought of very quickly, being familiar with the mechanics research scene, unanswered by this thread:
- How do mechanics which are incomplete or have regressed behavior work? For example, Zoroark's Illusion, if hacked into SwSh, can easily crash the game; if you break Illusion and then Dynamax, both Switch consoles crash. Do you just ban Zorua/Zoroark, revert to Gen 7 behavior, or do you just emulate all the new non-game-crashing mechanics, picking and choosing which ones to use?
- If a Pokemon switches out due to an Eject Pack stat drop from another effect, will Pursuit immediately move and damage the Pokemon switching out?
- How does Mirror Move, Snatch, Me First, etc. work with Max Moves? Do they interact like Copycat, reproducing the base move, or do they just fail?
- If a Pokemon is in the middle of Sky Drop, can it Dynamax?
- Are Dynamaxed Pokemon immune to Sky Drop?
- Phantom Force is blocked by Max Guard. Is Shadow Force supposed to do the same?
- Is Return's maximum base power still 102, or are we assuming Game Freak didn't reduce max happiness value to 160? (as a result making Return at most 64 BP and Frustration always better)
You can generate questions like these forever. Don't be fooled by that thread only having 14 items in its list. All of these questions I laid out, and others like them, can be answered reasonably, in my opinion. There are very few mechanics where you say "well there's just literally no precedent anywhere for this" and have to arbitrarily assign function. Still, it is nevertheless the case that
lots of National Dex mechanics are just chosen for the sake of balance or community preference rather than for how they
would behave.
The real problem is that all of these cases are just made up - while their underlying principles might be reasonable or not, the point remains that none of these interactions are possible to research and evaluate in SwSh
even with hacking. The behavior is simply asserted and assigned by the community. It's like asking "what if you could Mega Evolve in Gen 5"? You could say it'd work the exact same way, but there is no Gen 5 game with Mega Evolution so it's inherently a question that can have no answer, and a format replicating that will be just a fan mod. It's not official, and it doesn't follow how the games would really behave, because the fact of the matter is that there
are no Mega Evolutions or Z-moves in Sword and Shield and that isn't going to change.