Reference
Stat changes and critical hits
Moves, abilities and held items push a Pokemon's stats up and down mid battle. This is the part of Champions people get wrong most often, because the numbers are not percentages. They are stages, and a stage is worth different amounts depending on which stat it lands on.
Everything below is quoted from the game's own help text rather than worked out from play.
Stat Changes
A Pokémon’s stats can be boosted or lowered during a battle by effects from sources such as moves, Abilities, and held items. This is called a stat change.
Stat changes are measured in stages ranging from −6 to +6. The negative numbers indicate that a stat has been lowered, while the positive numbers indicate that it has been boosted. When a Pokémon is switched out of battle, these numbers will be reset to zero.
Stat changes can affect more than just a Pokémon’s stats, such as Attack and Defense. They can also affect a Pokémon’s evasiveness and accuracy.
When your Pokémon’s evasiveness is lowered, it will have a harder time evading moves. When its evasiveness is boosted, it becomes more likely that your opponents’ moves will miss. When your Pokémon’s accuracy is lowered, it will have a harder time hitting targets with its moves. When its accuracy is boosted, it is more likely to be able to hit targets with its moves.
The 7 things a stat change can hit
- Attack
- Defense
- Sp. Atk
- Sp. Def
- Speed
- evasiveness
- accuracy
HP is not on that list. Nothing raises or lowers a Pokemon's maximum HP during a battle, which is also why stat alignment never touches it.
Critical Hits
A Pokémon’s moves have a 1-in-24 chance of landing as a critical hit. A critical hit will boost a move’s damage by 50%.
In addition, a critical hit will ignore certain stat changes and status changes.
When a Pokémon gains a Critical-Hit Ratio Boost, its odds of landing a critical hit will be increased. The Critical-Hit Ratio Boost status has stages that range from 0 to +3. The larger the number, the more likely the Pokémon will be to land a critical hit.
Related
- Status conditions are what sticks to a Pokemon, like burn and paralysis.
- Battle conditions are what happens to the field, like weather and terrain.
- The damage calculator works out what any of it means in practice.
