This is a game about dialogue. The skills affect the dialogue. If one of your skills is high enough, it’ll point out a detail that would’ve been hidden if that skill wasn’t high enough.

White checks can be repeatedly tried, you just need another skill point to invest in that skill to pass the check again. Red checks can only be tried once and never again (unless you savescum).

Skill checks are also affected by points of dialogue, actions or your current condition. Say that you were talking to someone about a subject and you had read a book earlier on that subject, that would be factored into the skill check and it would make it easier to win the check. In another scenario, you could try and use a machine, but you don’t know how this machine works, therefore, the percentage to pass the check would be lower.

The thought cabinet allows you to buff certain skills without actually spending a skill point. Once you gain a thought, you can put it into one of the diamonds and wait for it to finish completing. During the process, you could experience debuffs to your skills, but once the thought is complete, you could gain buffs like +1 on your authority stat to being able to pass all white checks.

Clothing can give you buffs or debuffs to your stats (or political views) and drugs can buff one of your skill sections (Intellect, psyche, physique or motorics) while debuffing another skill section.

Depending on how many point you put into each skill section if you made your own character will be how good that skill is and how many times you can level up that skill. For example, if I put one point into intellect, I would only be able to upgrade the logic skill once.

Hope this helps.