There's a lot of new features in Pokemon Mystery Dungeon Rescue Team DX, one of which is the ability to power up your own attacks over time with something called Move Growth. We'll explain the basics of Move Growth here and you can raise it as fast as possible.
What Is Move Growth?
Move Growth is a special meter tied to every one of your Team's individual attacks that increases through continuous use. Every time you fill the little blue bar next to an attack, you slightly increase the attack's power, accuracy and power points (PP). This doesn't end when you leave a dungeon, so you can increase it over the whole course of the game, assuming you don't swap out your attacks for fresh ones. Move Growth is also shared between team members, so if everybody uses the same move, it rises that much faster.
How Does Move Growth Work?
Every time you use an attack in a dungeon, that attack's meter (visible as a small blue icon in a joystick next to it) raises a small amount, even if the attack misses the target or isn't very effective. For example, if you have a Squirtle using Water Gun, using it enough causes the meter to fill. Once full, it gets a minor permanent boost to attack and accuracy, and its max PP raises by one. The meter then empties and can be filled again. It's Mystery Dungeon's way of ensuring that moves that start off weak evolve and increase in power as the game progresses.
Does Move Growth Work On All Moves?
No, Move Growth only works on attacks that damage other enemies, not those that just raise stats or restore health. For example, Squirtle's Water Gun can be boosted and grown over time, but Withdraw isn't going to get the same treatment, having the same effect no matter how many times you use it.
How to Raise Move Growth Quickly
If you want to boost the power of your moves as fast as possible, you'll want to go to the Makuhita Dojo, at the furthest Southern point of Pokemon Square. Training here increases the speed at which your moves grow, though you'll need to find Dojo Tickets in dungeons in order to attend. If you've learned a new attack you want to empower as fast as possible, Makuhita's Dojo can be an excellent way to do so without losing anything in the process. Just keep using the attack you want to empower as much as possible for the best result.
If that was helpful, why not check out some of our other guides on Mystery Dungeon? We've got a full breakdown of how to link and delink moves here, as well as the basics of evolution here.