Korgoth said:
Well, with that kind of attitude you wouldn't be welcome at my table.
Oh, no.
FWIW, I don't even require a roll most of the time. If you're a sailor then you can climb rigging, no roll required (unless it's during a storm, or you're encumbered, then it's a Dex roll). If you're a woodsman you can track things, no roll required (unless there's something problematic with the trail, such as that they target has been making an effort to coneal its movements... then roll your Wis).
But, see, that's reasonable.
The problem is, there are a lot of unreasonable GMs - I've played with some and heard many stories about others - who use a rules-light system where "what a character can do" isn't well-defined and left up to GM fiat in an unreasonable fashion.
They're the sort of GMs who say to themselves, "Man, I want this guy to get away" and therefore simply make it impossible for the highly-experienced tracker to follow the trail, even when it's not plausible that the bad guy could cover his tracks that well.
It's not just about jerkoff GMs, though. There are plenty of corner cases, where the player has an expectation of what her PC can do which is at odds with the GM's idea of what her PC can do. To use an exaggerated example: historically, many sailors couldn't swim. If the player expects her former sailor to be able to swim because he's a former sailor, and the GM's assuming that he can't swim because of this historical fact, then you can run into problems when the sailor gets washed overboard during a storm.
Likewise, the more a player wants her PC to do, the more the GM has to rule on how it's done. That doesn't really happen any less in Third Edition D&D, actually; in my experience, no GM will make the PCs roll Climb checks when there's no pressure on them to climb quickly and they've got at least half an idea of how they're going to help the weak or inexperienced climbers up. That's just like your assumption that a sailor can climb the rigging automatically when there's nothing hindering him.
The more
ad hoc rulings the GM has to make, the less content I am as a player or a GM. I mean, at some point, it simply becomes easier to use a system where the rules are already written up.
It's also the case that your schema doesn't really seem, at first glance, to have room for actually getting better at something your background has trained you to do. If climbing in difficult conditions is always a Dexterity check, for instance, is Dexterity forever the only arbiter of climbing ability under pressure? Is it impossible to learn from experience and get better at climbing in difficult conditions? One response would be, "Oh, if you're deliberately practicing or you've done it a lot, I'll give you bonuses or reduce the penalties" . . . but that's just a half-arsed skill system.
I mean, I get that the way this stuff works is via negotiation between the player and the GM - or, worst case scenario, via the GM's arse. I just get to a point, pretty rapidly I'll freely admit, where it just seems
so much easier to use a rule that's been thought up by an experienced game designer.