Accuracy
Accuracy is an aspect of moves that determine how often they can hit their target. Accuracy currently can be any number between 30% and 100%, usually in multiples of 5.
In the Generation I games, accuracy was technically determined as a fraction of 256, with 255/256 being the highest possible value (FF in hexadecimal, the highest possible value before rolling over to three digits). Due to this, moves with 100% accuracy (which cannot miss unless a stat-altering move is used) technically have 99.6% accuracy, meaning that once in a great while they will miss for no reason whatsoever. This accuracy problem, which also extended to additional move effects such as paralysis and poison, was resolved in Generation II.
Many moves have an accuracy of "—%"; this either means that they affect no one but the user, affect the partner, or will not miss the target unless they use a move that gives them complete invulnerability for a turn.
Accuracy is raised by 30% if the Pokémon have the ability Compoundeyes, and by 10% if it or its partners have the ability Victory Star.
Formula for accuracy and evasion
The probability that a move will hit is calculated as follows:
Where:
- Abase is the base accuracy of the move (in percent - e.g. a base accuracy of 95 is counted as 0.95),
- Accuracy is the current Accuracy stat of the user (in percent - e.g. raising accuracy by three stages raises this number to 2), and
- Evasion is the current Evasion stat of the target (in percent - e.g. lowering evasion by two stages lowers this number to 0.6).
If P is greater than 1, the move will surely hit. In a 2-on-2 battle, it is possible for a move that hits two or three targets to miss some of the targets and hit others - the probabilities are calculated individually for each move.
