How to remove crit chance's RNG without ruining it

Change crit chance to a charge system. Every auto attack gives you a number of charges equal to your crit chance, up to 200 charges.

Ex: you have 30% crit chance - attack one gives you 30 charges, second attack gets you to 60 charges, the third to 90, fourth to 120. The fifth consumes 100 to crit, leaving 20, and gives 30 for a total of 50. Then 80, 110, crit down to 40. Etc. (The very first crit would take a little longer, but only the first.) Charges are never lost except when crit'ing, even after death.

When you attack with 100 or more charges, you consume 100 charges to crit that attack.

This removes the RNG factor of crit chance - you won't randomly crit 4 times in a row with 5% crit chance, and you won't randomly go 20 attacks without crit'ing when you have 30% crit chance. With this change, both parties can anticipate how a fight will go, rather than hoping someone does or does not crit during it.

Critical strike would be much more predictable, and would allow people to play around it much more. You can build charges on minions and wait to engage until you are about to crit for guaranteed front burst. You can anticipate when the enemy will crit and play around that. Etc.

For champions who can crit off of abilities, it would function the same as auto attacks - the ability builds charges when used and consumes charges to crit when over 100 charges.

Final note: Why 200 charges? It allows numbers like 30% crit chance to stay accurate, since it doesn't go into 100 evenly - otherwise it would be the same as 25% crit chance, crit'ing every 4th attack instead of every 3rd or 4th.