I don't think most people cheat on purpose, and even if I know someone is blatantly cheating, its not worth interrupting an otherwise fun game to call someone out on fudged dice rolls.
I do have 1 case that drives me up the wall though. Have a player with a Black Dragon Mask that misuses it frequently. I know he knows that because he's been called out in it before, and he has a copy of the item description. But he continually says it grants him immunity to acid damage, and that it lets him have a breath weapon equivalent to an adult black dragon.
Problem is I have a personal bias on the subject. I was there when we found it and he beat me in the roll-off. I would normally be fine with it, except I was on my 32ndish session and he was on his 2nd. So I am a bit butt-hurt about it. He does not sit at my table when I DM, so I resolved myself not to be the one who calls him out. But man it irks me when he brags about the things the mask doesn't actually do.
The most common errors I see, in general, are:
1. players starting with rolled stats. Or some other creative way so they start with an 18.
2. Players who think Hex affects saving throws.
3. Players trying to combine bonus action spells with non-cantrips.
4. Creative miscalculations on to-hit rolls.
5. -everybody- forgetting about concentration.
I do have 1 case that drives me up the wall though. Have a player with a Black Dragon Mask that misuses it frequently. I know he knows that because he's been called out in it before, and he has a copy of the item description. But he continually says it grants him immunity to acid damage, and that it lets him have a breath weapon equivalent to an adult black dragon.
Problem is I have a personal bias on the subject. I was there when we found it and he beat me in the roll-off. I would normally be fine with it, except I was on my 32ndish session and he was on his 2nd. So I am a bit butt-hurt about it. He does not sit at my table when I DM, so I resolved myself not to be the one who calls him out. But man it irks me when he brags about the things the mask doesn't actually do.
The most common errors I see, in general, are:
1. players starting with rolled stats. Or some other creative way so they start with an 18.
2. Players who think Hex affects saving throws.
3. Players trying to combine bonus action spells with non-cantrips.
4. Creative miscalculations on to-hit rolls.
5. -everybody- forgetting about concentration.