Stats are a primary function of the game. Each stat is separated into different categories of Attack, Defense, Special Attack, Special Defense, Speed, and HP (Hit Points). Belly is also a stat exclusive to Pokémon Mystery Dungeon games. In PMU 5 and PMU 6, upon leveling up players would gain points that they could spend to increase stat values, but in PMU 7 stats became set off each Pokémon's base stat total for balancing purposes and accuracy to the games.
HP, Attack, Defense, Special Attack, Special Defense are normally defined by this formula:
The current value of each of those stats for the active Pokémon can be seen in the team panel at the top of the game screen.
These six stats can have flat increases by items such as scarves, family items, and dusts and silks. Abilities (such as Flare Boost or Hustle) or other items such as Choice items or Pokémon-specific items will indirectly increase these stats; they will not be shown visually in the team panel but will be in effect all the same.
List of Stats[]
Attack[]
The Attack stat determines how much damage a Pokémon deals when using a physical move.
Defense[]
The Defense stat determines how much damage a Pokémon receives when it is hit with a physical move.
Special Attack[]
The Special Attack stat determines how much damage a Pokémon deals when using a special move.
Special Defense[]
The Special Defense stat determines how much damage a Pokémon receives when it is hit with a special move.
Speed[]
The Speed stat is used in the calculation of the delay received when being hit by an attacker, informally known as "hitstun".
When a move is used, a timer ticks, and when it completes, the user can attack again. This timer is on a per move basis, otherwise known as the cooldown. When attacked by an opponent with a higher Speed stat, regardless of by how much, this timer increases per hit a Pokémon receives. In extreme cases, a higher Speed stat along with an incredibly high attack speed (a faster/lower move cooldown) outspeeds the ticking of the cooldown, effectively stunlocking an opponent.
Hitstun can occur from the basic 
attack and even from attacks that dealt no damage or are absorbed from means like Water Absorb. Hitstun however doesn't seem to occur from status moves. Attacks with increased priority are known to bypass any applied hitstun and be used regardless.
The Speed stat otherwise has no known effects. A Pokémon with a generally high speed will only gain the benefit of avoidance of being hitstunned, and hitstun does not apply when Speed stats are tied.
HP[]
Hit Points, or HP for short, determine how much damage a Pokémon can receive before fainting.
Evasion[]
Evasiveness affects the probability of dodging an opponent's move. A full list of Pokémon with access to evasion increases can be found here.
Accuracy[]
Accuracy affects the probability of hitting a target.
Movement Speed[]
Movement speed determines the quickness of a Pokémon's movement. Movement speed cannot be altered outside of the None (dungeons) or No Death Penalty morals, or arenas.
Belly[]
Belly is a stat that depletes over time for the active Pokémon, in dungeons only. Every 10 steps, 10 basic attacks, or two turns will deplete 1 Belly. The current amount of Belly can be seen in the 
menu. The base Belly size is 100, and it can be increased eating certain consumables while full, but some food items increase Belly size without it needing to be full. Each member of the team has an individual Belly stat.
Belly will display three messages in the Battle Log when it reaches 20, 10, and 0. When Belly is fully depleted, the Pokémon will lose 5 HP every five steps until the Belly is above 0. Going from a dungeon floor to a set floor or leaving a dungeon entirely will reset Belly to full, including resetting any size increases. Most edible items will fill Belly by some amount, as well as all seeds, Berries and Gummis.
Some held items affect Belly:
- A
Stamina Band doubles the amount of steps, moves and basic attacks until Belly loss - A
Diet Ribbon decreases steps until Belly loss to 5 - A
Heal Ribbon decreases steps until Belly loss, but increases HP regained from moving if Belly is above 0 - A Tight Belt causes Belly to not lower at all from moving outside of walls
- A Munch Belt decreases turns until Belly loss to 1 and basic attacks until Belly loss to 2, but increases the holder's attacking stats
- Leftovers cause taking turns or using basic attacks to not lower Belly
Technicalities[]
The counter for usage of turns is shared by all Pokémon, rather than only counting turns used by the active one. Steps will also be counted even if outside of a dungeon. Meaning that for example, 7 steps can be taken before entering a dungeon, and when a dungeon is entered, 3 steps inside will lower Belly.
Temporary Changes[]
Using certain moves, items, or certain Abilities coming into effect can increase or decrease a stat (other than HP or Belly) for the duration a Pokémon is on a map/dungeon floor, or the duration the item is being held or kept in the bag. These modifications also won't be seen visually in the team panel. Temporary stat changes can be reset back to normal by some moves, or by stepping on a Wonder Tile.
Stat changes for stats other than movement speed can go up to 10 stages, rather than 6 like in the main series. How many stages a stat was affected by a change can be told by the message in the Battle Log. While a stat can be lowered from its increases, a stat that's gone into the negatives from stat drops currently does not have an effect on move calculations.
| Change | Text | Stages |
|---|---|---|
| Increase | [Pokémon]'s [stat] rose slightly. | 1 stage |
| Decrease | [Pokémon]'s [stat] fell slightly. | |
| Increase | [Pokémon]'s [stat] rose sharply! | 2 stages |
| Decrease | [Pokémon]'s [stat] fell harshly! | |
| Increase | [Pokémon]'s [stat] rose drastically! | 3+ stages |
| Decrease | [Pokémon]'s [stat] fell drastically! | |
| Increase | [Pokémon]'s [stat] can't go higher! | Max |
| Decrease | [Pokémon]'s [stat] can't go lower! |
Movement speed can be altered by three stages. When increased, it affects speed when running with 
. When decreased, the Pokémon can no longer run, or its walking speed becomes slower. Running at normal speed can be considered transitioning to +1 movement speed.
| Text | Stage |
|---|---|
| [Pokémon] is at quarter speed! | Stage -3 |
| [Pokémon] is at half speed! | Stage -2 |
| [Pokémon] was slowed! | Stage -1 |
| [Pokémon] is at normal speed! | Stage 0 |
| N/A | Stage +1 |
| [Pokémon] is at double speed! | Stage +2 |
| [Pokémon] is at quadruple speed! | Stage +3 |
"Attack speed" is a term commonly used to refer to the speed of one's moves, but it is not part of the stats mechanic. Move cooldowns can be lowered through Abilities or Family Items, on top of moves with naturally low cooldowns. A list of Pokémon with access to attack speed increases can be found here.