I'd also say that KotOR is, despite being one of the most prominent games to use the d20 system, one that probably casts it in the worst light.

It's very simplified, kludgy, sometimes deviates from the base system entirely in ways it refuses to explain (Persuasion DCs are character level scaled so if you aren't maxing investment in it at every level it basically becomes almost impossible to succeed), and sometimes in ways that actually make more sense for a CRPG* (it does the thing where higher investment in certain skills save resources, repair and computer let you spend less parts/spikes to pass the same checks instead of rolling for them), and not terribly well balanced (especially with the class that isn't from the rulebook, the Jedi Sentinel which falls between the two stools of combat and powers and is always the worst option of the three).

* Because out-of-combat checks in CRPGs are savescum magnets, it's better to not use highly determinative randomness on them, so skill reducing cost or orthogonal risk** is better.

**eg. Hacking in the original Deus Ex was just a countdown timer that went slower the higher your level, it started as soon as you started to break in and counted down as you were in the system, so you had to break in and do all of the things you wanted to do with the computer in that limited amount of time, the minigame in DXHR/DXMD is less tense and interesting and you can savescum it for the best outcomes.