No no no, you don't understand, you're not allowed to take action on Tera until it's existed for 3 months and totally monopolized meta progression and made it impossible for the metagame to develop in a healthy way; but once 3 months have passed, it'll be too entrenched in the meta and you won't be allowed to take action on it since the metagame has progressed to revolve around it (and SPL has started).
Don't you see how reasonable I am? Clearly no one else had given any thought about whether it would be best to give this mechanic time before me. I am the only Pokemon player with any restraint whatsoever. Bask in my oh-so-nuanced intelligence.
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On a serious note, I will comment on the prediction point: every mechanic forces "predictions" of a sort, as do most moves and Pokemon. This isn't unique to Tera. But most "predictions" in mons, in the absence of Tera, are not actually true "predictions"; instead, you take a look at what you need to win and try and find a good midground that advances your own gameplan while not letting your opponent do the same. Sometimes you need to make risky plays, yes, but outside of HO vs HO games, it's typically uncommon for the entire game to come down to one or two big predict turns (it does happen in some endgames, of course).
Tera, however, places a big emphasis on one or two prediction turns deciding the game. There's obviously the direct impact — stuff like how Teraing into a defensive type allow you to avoid a revenge kill and continue a sweep — but there's
also the fact that your singular Tera is a very valuable resource, and so every turn you click Tera, you're risking a lot to try and exploit your incremental advantage. With Z-moves, this was not an issue insofar as you commit to Z-moves
before the game in the builder; there was still a cost to using your Z-move since you can only do it once, but it wasn't as limiting of your future options as the "resource" of being able to pick your Tera was expended up-front, rather than being forced to boil down to a correct prediction.
As an example, suppose your opponent has a Gholdengo in against your Tera Fairy Espathra. Espathra is in range to die to a super effective Shadow Ball or Make It Rain, but not a neutral one; and it 2hkos Gholdengo back no matter what. This is a situation that blatantly comes down to Tera predicts; but when you make the decision to Tera or not, you aren't just risking one Pokemon. Espathra is a very snowbally mon, and if your opponent is relying on Gholdengo to answer it, they probably don't have a great response otherwise; so there are three real outcomes:
- You predict correctly and win.
- You predict incorrectly and lose Espathra, and:
- if you Tera'd, you lost your Tera (but at least your opponent's Gholdengo is now -1 SpAtk).
- if you did not Tera, your opponent has a fine (if damaged) Gholdengo in.
Hopefully you can see how much Tera inflates the stakes here. The best-case outcome is you winning the game, and the worst-case is you losing a wincon
and your Tera. Your opponent could maybe try and hedge that you're slightly more likely not to Tera since that means the worst-case is less bad for you, but you can see how this quickly ends up in a bunch of
mindgames. My point is that the gulf between success and failure is simply too high here for this to be something we tolerate happening regularly in the metagame.
And "regularly" is the key word here; every metagame will have games come down to "50/50s" and predictions every now and then, but Tera does it early and often. Anyone who's played a lot of ladder games has probably had multiple situations similar to the above happen. Espartha is a particularly bad offender here, but there's plenty — Roaring Moon, Annihilape, Dragapult, Tera Normal Dragonite, all of the Trick Room abusers come to mind as Pokemon where these sorts of situations honestly feel like they happen more often than not. Moreover, a lot of these Tera 50/50s happen early in the game, whereas "traditional" 50/50s that actually decide games usually occur on the last few turns of a very-even battle; I can tolerate 50/50s a lot more if they're used as a coinflip to resolve a close game than if they just decide one on turn 5 (at the very least, it makes games exciting).
To that end, I am interested some sort of policy that requires the player to choose who's going to Tera before the battle (e.g. restricting Tera to only one Pokemon or whatever), so that this cost is somewhat paid up-front rather than creating a prediction burden on every single turn of the game. That is to say,
simply making Pokemon declare their Tera types before battle nerfs Tera but it does not (alone) fix this problem.