It was kind of wild going from D&D to games that don't have tons of HP.
Players make different choices when they have a maximum of 7 health, and a random mook with a baseball bat hits for minimum 2, maximum "well if the dice keep exploding..."
NPCs don't get death saves. If you're a player character you probably already have more than 4hp. Unless you're a wizard with 6 or 7 constitution… If you are a wizard can you teach me some magic tricks?
A 1/4th chance of of death is better than none. Then I just need to make sure to lower my constitution and find an attacker with good dexterity. That makes it 3 quarters. If we allow the use of the "Oops all 6s" joker from Balatro that becomes a 4 quarters (100%) chance unless I for some reason turn out to be a player character.
18s isn't even the maximum. If you are stabbed by another commoner, they have only a chance of 65% to hit your ac, so the average damage per turn is 2.5*0.65=1.625
On average, you would survive 12s and become unconscious after 18s, dying after 24s from two more direct attacks