I used to play competitive WarMachine which uses a 2d6-based system (with options to buy additional dice through various mechanics). Gives a relatively stable Gaussian probability curve (ie: you are about 50% likely to roll a 7-or-less, about 90% of rolling a 4-or-less, and so).
If an opponent has a DEF of 12 and you have a MAT of 6, you need to roll a 6 or more to hit (tying or surprising their DEF value). If they have ARM20 and you have POW10, you need to roll an 11 to inflict a wound… unlikely, but not impossible, but you can add a die through Charging, another die if you have Focus to spend, and so on…
Right. All that to say that there was a famous (in the WarMachine community) worlds event where a player needed to roll a 4 or more and had 3 chances to do so. 90% chance three times is mathematically almost 100%… but of course he lost the roll, which meant he lost the game, which meant his team (Australia) lost the tournament.
James has since left WarMachine… and I think he’s come back to it recently (casually). Australia did end up winning the following year, but yeah. Probabilities.
I once played a guy who had sets of dice for specific purposes, all casino cut: yellow for Courage checks (where you want to roll low), red for hit dice (high rolls) and blue for damage (again, high rolls). It bothered me a little, but not enough that it stopped me from stomping him at the tournament.
I tend to get bothered more by systems that hinge on single die rolls, since “buckets of dice” isn’t really an accurate mathematical system. Infinity uses multiple d20s (the worst of all systems), but since I don’t play competitively I can laugh off the ridiculous results more easily. SW Legion uses custom d8s for attacks and custom d6s for defense, and the game often swings very, very heavily on those defense dice. But, again, not attempting to be a balanced system and so it’s more forgivable.
Anyway. Yeah. Gaussian curves are fun.