This "unfair RNG" issue was big in Dota 2 (a popular video game) for a while. They ultimately implemented something similar and AFAIK now all "random" effects use it.
Not quite all; there are still a handful of skills that use a discrete or flat distribution but practically all attack based changes use the pseudo random distribution.
For more info:
http://dota2.gamepedia.com/Random_distribution
RNG stands for Random Number Generator. It is used colloquially, in gaming, to refer to the probability of certain random events or the underlying implementation of them.
yeah but now it applies for I think everything. The last one to go was Spirit Breaker's bash. Prior to that PA's crit.
Funny thing is that with PRNG you can "warm up" via farming creep camps so if you don't crit in say 5 attacks you can go look for a fight and be "guaranteed" a crit with your first swing.