I'm strongly of the mindset that cheating only means taking a dishonest and unfair advantage over another person. Changing the rules of the game is not cheating, it's house ruling - in tabletop discussion, that's part of what we call Rule Zero. If I'm not in competition with another person, it's just playing by my own rules.

I remember one HL1 CS (Specialists Mod) LAN party I was in where we all turned on Matrix Vision and multiplied the slo-mo timer. It was great - utterly chaotic, but everything was equal.

So no, I don't cheat in games. I just play by my own rules as long as it doesn't hurt anyone else. And if I do play multiplayer, I try to bring my house rules to them. I've never had any person accuse me of cheating when I ask about various options. TBH, the closest I come to cheating is turning on all of the assistive features - colorblind mode, target highlighting, auto target, sound notifications in minimaps, custom keybinds, and whatever else is in the menu. Everyone else can also choose to do that, and I'm just as happy if everyone I play with has those same things.