Grinding Gear Games, released part 2 of their community of questions and answers about the game mechanics. The team discussed monster kills, various effects, mine detonation, and more. It was quite extensive, and you should read it if you like the details.
Part 2 also includes some extensive answers. Ironically, it also includes a monosyllabic answer to the question of whether spell evasion and block are performed separately for each hit for the same spell. The team simply replied, ” Yes.”
Other questions, such as the question of a critical enemy spell, critical on each hit, or rolling separately, received much more extensive answers. In short, it all depends on the spell. But games with grinding gears have expanded,
“The way chances work is you have a percentage chance to do something, which is a number from 0 to 100. The game rolls a random number from 0 to 99, and if the chance value is higher than (not equal to) that random roll, you do the thing. It’s pretty easy to see that this gives correct behaviour; the random roll can only go as high as 99, so a chance value of 100 will always happen (for performance reasons, the roll is often skipped for this case), and a chance roll of 0 is never higher than the random roll, so a chance of zero never happens. But a less obvious consequence of this, and one which critical strikes in PoE take advantage of, is that the random roll and the chance are fundamentally two separate values – and you need both to evaluate whether a crit happens.”
Like Part 1, this Part 2 is chock full of great information if you like the nitty gritty of Path of Exile.