After posting this Thief thread recently I had another couple of little thoughts of only miniature merit.
My Double Dexterity house rule puts a huge premium on the Dex score. For my own games, this is fine because I let players put their scores wherever the hell they want. If you're gonna play a Thief, you'll almost certainly put your best score in Dex. And I think that's perfect for my campaigns.
But what if you run games a little bit more close to rules-as-written? Meaning, what if you do the whole 3d6-in-order thing? Then it is probably going to be the case that only players who happen to roll a good Dexterity will choose to be Thieves. In that case, perhaps an even simpler house rule would suffice: Thieves add +25% to all skills other than Climb Sheer Surfaces and Hear Noise.
I mean, this isn't a genius move or anything. It's a blunt instrument. The Thief skills are too low, we all agree*, and this is just a brute way of addressing that fact.
Another idea for the 3d6-in-order crowd (or anyone, I suppose) is to give Thieves a randomized bump. The player rolls dice for each skill at the point of character creation and adds the result to the skill. This one just hit me, actually. And I kinda like it, in principle, because it makes all Thieves very unique in their skill sets. So let's explore this by looking at some ways to randomize it.
1d100: Just roll 1d100 and add the result as your bonus. Uber swingy! You might start with Hide in Shadows 21% and Pick Pockets 105%. But what an excellent reflection of individual thievery.
1d20: Far more modest, low key. Blah.
3d20: Now this is interesting. You'll have an average bump of 30 points, which puts your skills around the 40%-50% range that the Double Dexterity rule gives you. But it disentangles skills from your Ability score, if you like that sort of thing.
3d6 Exploding: Hmm... average of 10 or 11? With the exploding bit I'm not sure how to do that math. I suppose the average would be higher than 11 but not by too much. Yet you have the potential for a huge skill bump if you luck out and roll a lot of 6s.
Off the cuff... out of all these ideas I actually like the +1d100 one the best. It's super swingy but that really adds some flavor to your PC right out of the gate. Like why is Sniffle the Sneak total shit at picking pockets but he can melt into the shadows like a magic ninja? Perhaps he gets nervous around people.
Ideas and shit.
*We all agree.