an underappreciated game design skill is the ability to just... sit and think through all the implications of a system by simulating the entire game in your head. you can't just think through the consequences of a change; you need to think through the consequences of those consequences
This is so much of my work as an accessibility design specialist!
"This cue needs to be extremely clear to players with an audiovisual pairing. It also shouldn't play continuously or be too large because that draw too much focus for various cognitive disabilities and potential motion sickness risk. Oh it's using a symbol? That's good for quick identification but where is the player taught that symbol and how easy is it to reference? Is the symbol high contrast but not so high contrast that it causes astigmatism issues? Is it large enough to be seen with low vision without obscuring other important information?"
The knowledge and ability to consider how design decisions affect players with very different access needs at the same time is why my job exists at all.
Absolutely! You need to frame every possible interaction against every possible use case, which is a TON to keep track of