Evasion Mechanics
In Heartache, a unit that has positive evasion stages will have one half-dodge per stage every turn, with two half-dodges making a full dodge. This explanation is intended to demonstrate precisely how dodges work and are calculated, including how they interact with units that have a positive accuracy stage.
Suppose we have a battle with Jean the Vulpix, Dave the Poochyena, and Gabriel the Slugma going up against Soda the Zoroark. Soda has +3 evasion, and Dave has +2 accuracy. Soda's +3 evasion gives him three half-dodges for the turn, represented by blue circles.
Acc
Eva
Dodges
Suppose that Jean moves first. She realizes she knows the move Swift, which is a Sure Hit! That means it bypasses negative accuracy and positive evasion completely - it will hit Soda and simply ignore his dodges.
Acc
Eva
Dodges
→ Jean's Swift →
Sure Hit move - ignores evasion/dodges completely and hits for full damage
While Soda has been hit, he still has three dodges, just like before, because he could not attempt to dodge the Swift.
Dave moves next. Since Dave has +2 accuracy, his accuracy stages and two of Soda's evasion stages will 'cancel each other out' - for the duration of Dave's turn, Soda will only be able to use one half-dodge. Dave's accuracy stages also will not cancel out any accuracy costs or give him extra Tempo for his attacks targeting Soda - those stages are going into countering his evasion instead!
Acc
Eva
Dodges
Dave attacks with Bite - Soda will be forced to use up his only available dodge to half-dodge his attack.
Acc
Eva
Dodges
→ Dave's Bite →
+2 Acc cancels out two of Soda's available dodges - the remaining half-dodge is used up, and Soda is hit for half damage
Dave uses a second attack, Rock Smash; thanks to the accuracy canceling, Soda can't use the dodges he has remaining at all.
Acc
Eva
Dodges
→ Dave's Rock Smash →
+2 Acc cancels out both of Soda's remaining dodges - he has none left, so he takes full damage
Gabriel is up next. Unlike Dave, he has no accuracy stages - so Soda's remaining two dodges are now active again.
Acc
Eva
Dodges
Because Gabriel doesn't have a Sure Hit move like Jean does, Gabriel chooses to feint with a weak attack to use up Soda's dodges. While Gabriel's cheapest move in stamina terms is Smog, Smog is only 70% accurate - and if Gabriel used Smog without paying the 6-Tempo accuracy cost, it would already be a half-dodge, so Soda would only have to use up one of his two remaining half-dodges to dodge it completely!
Since Gabriel doesn't want to pay that much Tempo or have a second move get half-dodged, Gabriel chooses instead to feint using Ember, which costs a little more stamina but is 100% accurate. Soda is forced to use his two remaining dodges to fully dodge the Ember.
Acc
Eva
→ Gabriel's Ember →
Soda has two half-dodges, which make a full dodge; both of them get used up, and Gabriel's attack is completely negated
Now Soda's dodges are gone, and Gabriel can go in for a stronger move with Incinerate:
Acc
Eva
→ Gabriel's Incinerate →
Soda has no dodges remaining and takes full damage
On the next turn of the battle, Soda gets another stockpile of three half-dodges for his +3 evasion stage, and the players will once again have to choose how best to tackle him. If he had used another Double Team on his turn, he would now have +4 evasion and thus four half-dodges!
Acc
Eva
Dodges
When going up against an opponent with evasion stages, there are two main strategic routes to taking them down: to attack them with Sure Hit moves or units with positive accuracy stages, who can bypass their evasion; or to feint against them, using cheap, weak attacks at the start of the turn to deplete their dodges and then go all in when they will no longer be able to dodge. Choose the best strategy or mix of strategies for your current situation!