I’ve been digesting the rules and find myself stumbling over the idea that advantage with a zero attribute involves rolling 2d20 and keeping the high one. Whereas advantage with a 1 in an attribute (1d4) is 1d20 + (2d4 keep the highest 1). It makes sense keeping in line with the mechanics but the maths seem a little off. Advantage with a zero attribute gives a 51% chance to success on a CR 15, up from 30% for a straight 1d20 roll. To get that same chance with an attribute 1 you would have to have your attribute die explode. Said a different way, 75% of the time you’re better off having a zero in an attribute than a one, provided you have advantage on the roll.
Also, because you are rolling 2d20 and keeping the highest you are doubling your odds of rolling a 20 and having the d20 explode. This is actually a pretty big deal as an extra 5% chance of exploding a 20 with the way damage is calculated is a huge advantage.
Is this just a quirk of the system or am I missing something (very possible)? I’d be inclined to just give a player with a zero attribute a +1 in a situation where they had advantage. Definitely less interesting, but helps to keep attribute scores of 1 worthwhile.