5e - Thief Climbing Advantage?

[EMIW]

I'd like some thoughts on a potential alteration I'm thinking of making to a sub-class feature in my game.

It's been pointed out to me by a player (Rogue - Thief) that their feature Second-Story Work makes their character faster at climbing, but not necessarily better. At first I thought they were the same thing, surely? But then I realised that if they are climbing a difficult surface (slippery, few handholds etc.) and have to make an Athletics check, they don't actually get any advantage (little a) over the other characters not trained in climbing.

So I've thought of two options:

1. A rule just for Thief:
Add a line to Second-Story Work along the lines of "In addition, when you make a Strength (Athletics) check to climb a difficult surface, you make the check with Advantage." To reflect that the Thief is better experienced at climbing, with surer footing, but may feel unfair to other players.

2. A rule for everyone:
"When making a Strength (Athletics) check to climb a difficult surface, you may halve your distance travelled to gain Advantage on the check." So if they wanted to slow down and pick out a surer way up, they can do that, and the Thief can still go faster because their normal climb speed is further. This feels fairer, but on a full distance climb you'd end up with regular characters moving 7.5ft, a bit difficult within 5e's rules, and I wouldn't want to say they can only climb 5ft just for the sake of a grid.

What do people think would be the better option?

[Wynamoinen]

TBH, I don't think either is all that necessary. The idea that thieves are better at stuff (like lockpicking, sneaking, climbing, etc) than other classes is represented by Expertise in 5e. If your thief wants to be a super climber, they should put Expertise in Athletics, IMHO. Or carry around a rope and grappling hook. Or get a magic item that helps.

That said, if I had to choose... 5e is about simplicity of rules, and making big sweeping changes is always more dangerous. Your first rule is more simple than the other (you just get a benefit, rather than constantly making a rules-based choice to trade one thing off for another), and it's narrower - it applies only to thieves. Your second rule is a buff to barbarians and fighters; they'll feel less need for the advantage (they're strong and are more likely to have athletics proficiency), and so they'll tend to climb faster than other classes. So if I had to choose, I'd pick the first.

Climbing is rare in any game I played, and climbing difficult surfaces even rarer yet. If the thief hasn't assigned a proficiency to althetics, is it actually a problem that for very rare and very difficult situations, they are also bad a climbing them? Is this actually a problem that needs to be 'solved'?

[zevonian]

So, you're going to set up an encounter where speedily climbing a wall is important, yes? What about just asking the player of the Thief to make a perception check when they see that wall, and then saying, "You know, since you're a Second Story Worker, I'm going to give you Advantage on your Athletics check, just because you see where the best hand holds and foot rests are."?