Move Power in Double Battles
In Pokemon battles, each attacking move that is used has some form of damage. In a double battle, most of the moves used in a single battle keep their original power. However, some moves do not. The basics are this: if the move hits more than one target(Heat Wave or Surf for example), the real move power is reduced to 75% of the original power. So, if in a double battle you use Surf, the power against each target would be: (95 * .75), or 71.25. Now, in pokemon battles, when there is a decimal after the whole number(in this case, .25), it is just ignored by the game's damage calculator. So, the power of Surf would be 71 against each opponent(in this case, including your ally!)
Now, some moves hit two pokemon and some moves hit three. If a move only hits two opponents, the same formula as above applies. If Heat Wave is used, it's power against both opponents is (100 * .75), or 75. Pretty straightforward. What about a move's accuracy? What if it has an accuracy of less than 100? Is the accuracy the same on both opponents? Well, no. Let's take the move Rock Slide for example. It's accuracy is 90%. What about against two opponents? Well, here is the formula. You take the accuracy and multiply by itself. So, (.9 * .9) = 81; it has 81% chance of hitting both opponents. Now, a good thing about moves that hit all three targets is that they all have 100 accuracy; so you know that it will hit every target.
Side effects of a move are usually what is most important when it comes to percentages. If the aforementioned Rock Slide has a 30% chance of flinching an opponent in a single battle, what happens in a double battle? Is it 30% against each one? Does it magically double or not have any effect? Are there too many rhetorical questions? Regardless of the last question, the chance of extra effects are different. So, Rock Slide has 30% chance of flinching an opponent; what's the chance of flinching both opponents or neither of them? In a double battle, it goes like this: (chance of extra effect[in this case, .3] * itself[.3]) = .09, or 9% chance of flinching both opponents. The chances of flinching no opponent are(chance of not flinching[.7] * itself[.7]) = .49, or 49% of not flinching either opponent. The chances of it flinching one opponent or the other is (1 - (chance of flinching both[.9] + chance of flinching neither[.49]) = .42. So there is a 42% chance of hitting one opponent but not the other.
Now, some moves hit two pokemon and some moves hit three. If a move only hits two opponents, the same formula as above applies. If Heat Wave is used, it's power against both opponents is (100 * .75), or 75. Pretty straightforward. What about a move's accuracy? What if it has an accuracy of less than 100? Is the accuracy the same on both opponents? Well, no. Let's take the move Rock Slide for example. It's accuracy is 90%. What about against two opponents? Well, here is the formula. You take the accuracy and multiply by itself. So, (.9 * .9) = 81; it has 81% chance of hitting both opponents. Now, a good thing about moves that hit all three targets is that they all have 100 accuracy; so you know that it will hit every target.
Side effects of a move are usually what is most important when it comes to percentages. If the aforementioned Rock Slide has a 30% chance of flinching an opponent in a single battle, what happens in a double battle? Is it 30% against each one? Does it magically double or not have any effect? Are there too many rhetorical questions? Regardless of the last question, the chance of extra effects are different. So, Rock Slide has 30% chance of flinching an opponent; what's the chance of flinching both opponents or neither of them? In a double battle, it goes like this: (chance of extra effect[in this case, .3] * itself[.3]) = .09, or 9% chance of flinching both opponents. The chances of flinching no opponent are(chance of not flinching[.7] * itself[.7]) = .49, or 49% of not flinching either opponent. The chances of it flinching one opponent or the other is (1 - (chance of flinching both[.9] + chance of flinching neither[.49]) = .42. So there is a 42% chance of hitting one opponent but not the other.