shilsen said:
How unchallenging are the things that your hero is attempting, if rolling lousy on hit points won't seriously hinder - if not render impossible - his chances of succeeding? I could give my PCs max on all hit dice and they'd still have a seriously hard time in my game. Now if your game is focused on being gentle and mollycoddling PCs and you have trouble challenging PCs, then clearly rolling hit points is the way to go, because they might roll really badly and make things easier for you.
Er, well, Neverwinter Nights 1 has random hit points (though you have the option of just taking maximum instead - yes, it does seriously work like that) and the absolute mathematical worst you can be down is 185 hit points if you somehow get the minimum possible hit points at every level and take a d12 HD class at every level past 3. In practice, since no one would ever actually be down 185 hit points from someone else of the same build, it wasn't enough of a problem to
really mess with the difficulty levels of things.
And this is with the worst random hit points system possible, one where the only randomness is HP you don't get, rather than 3e D&D's default which assumes you can't just take the maximum possible instead, so rolls will tend to be around an average rather than be 100% negative, and people will have more HP than the average equally as often as they will have less, and due to the bell curve effect of rolling so many dice for HP, will not have HP approaching the minimum or maximum possible very often.
(That said, I'm glad they removed random hit points from Neverwinter Nights 2, because in almost every single instance I re-leveled until I got maximum HP and this slowed leveling down to a terribly annoying grind.)
EDIT: As I've said, if you want random HP in 4e, I'd consider something like changing a Rogue's HP from 12 + Con score at first level with 5/level thereafter to 7 + 2d4 + Con score at first level with 3+1d3 thereafter, for a maximum possible swing of 64 HP.
