Chance of a unit to die in x hits is (imo) the best way to display who is winning durability, and by how much.
If you want to show chance of death after x hits at y% hit, where x is also the amount of hits your unit survives, the formula is:
CoD = y/100 ^ x
For example, if Mia is getting 3HKO'ed at 20% real hit, her chance of death after 3 attacks is
20/100 ^ 3
= .2 ^ 3
This way only works if you want to calculate a unit's chance of death at the number of attacks they're getting killed in. If you have a really large durability advantage, that's usually sufficient. If not, however, you can use Reikken's awesome death chance calculator. This topic contains discussion on what formula is used for this, so if you're interested just look through it.
Chance of Critting on a double
Fairly simple, but listing it anyway.
If a unit is doubling with a certain crit% percentage, you can calculate his chance to crit at least once out of those two attacks as follows:
Chance not to crit on a single hit: a = 1 - crit%
Chance not to crit on a double hit: b = a ^ 2
Chance to crit at least once on a double hit = 1 - b
Chance of triggering something
For example, a Zihark has 20% crit, 30% Adept and 20% Astra.
Like above, you simply calculate the chance not to activate any of these, and substract that from 1.
.8 (no crit) * .7 (no Adept) * .8 (no Astra) = .112 (none triggered)
1-.112 = .888 = 88.8% chance of triggering one of these
Combining this and chance of critting on a double, I'm sure you can work out the chance of triggering any of these on a double.
Edited by Mekkah, 19 July 2009 - 04:13 PM.