Why are there no moves with -2 priority?

[ThePokeCorral]

This is something that I've been meaning to get around to asking for a couple years now. 😅

For those who don't know what I'm talking about, a brief history of priority brackets. In Gen 1, the only moves with non-default priority were Quick Attack with +1, and Counter with -1. (Mirror Coat didn't exist yet.) In Gen 2, a few more moves were added with +1 and -1 priority, and the protection moves were added that had +2. Gen 3 was when priority brackets really expanded; but what's relevant here is the creation of the move Focus Punch. Focus Punch was, reasonably, given the highest priority bracket lower than Vital Throw (which "goes last but never misses"), and a bunch of moves that were previously -1 alongside Vital Throw (Counter / Mirror Coat and Roar / Whirlwind) were moved to be even lower. But, weirdly, Focus Punch was given -3 priority where Vital Throw is -1, and the -2 bracket was left empty. The -2 bracket has remained empty ever since.

This is weird. Why isn't Focus Punch and its ilk -2, and everything below it one level higher? This causes there to be one more negative bracket than there needs to be; without this oddity, Trick Room would be -6 and there would never have been a -7.

My best guess is that, at some point during the development of Ruby and Sapphire, there was a move with a priority inbetween Vital Throw and Focus Punch, and before launch that move got removed or put in a lower bracket. This theory is supported by the fact that when Vital Throw was removed from the game in Gen 9, the -1 bracket is now empty instead of moving everything below it up. But if that's the case, I'd still like to know (1) the details of how that happened if they are known, and (2) why, in all of this time, they have never corrected this, since whatever was supposed to go inbetween Vital Throw and Focus Punch is clearly never coming back.

 

[Devalue]

Knows of no particular reason. Presumes the same thing as you: originally placing a move there that was later moved or cut. Glanced down the list of new moves in Generation 3. Could see something like Block, Imprison, Endeavor, or even Slack Off being at -2. Alternatively, some kind of doubles move or a Protect punisher.

As for why not fix it: Probably seemed simpler to leave it as-is. Never presented this information in list form in-game. Copy/pastes information easily enough. Risks messing up the other developers' memories by changing the priority of moves you do not want to change, even if the relative position remains constant.

Alternative guess for why: Potentially coded it in such a way that would require deleting other parts of code. Might go down the list and fill priority slots. Checks for a -6 or -7 priority move when none exist. Cost time to fix that was better spent elsewhere.

(Disclaimer: Has never looked into how the battle code works. Speculates with no real information or knowledge to back up any of the above.)

 

[Corveone]

I guess it's allways possible that they had another move(s) in mind originally intended for priority -2 but ultimately scrapped them, and/or decided to leave that empty space in case later games would need it for something specific.

By now it's probably just a matter of "if it's not broken, don't fix it". They could have re-arranged all the negative priority moves by changing multiple code lines, but it's not worth the trouble if what they currently have is working.

No idea how Prankster would fit into the equation. I imagine it makes sense to leave at least one negative priority slot empty just in case developers want to make sure that some -1 status move designed to move last doesn't get boosted to normal priority.