A Humble Proposal For BX Thief Skills

 If you talk to BX/OSE afficianados, they will justify the maligned thief abilities in a variety of ways, ways that I sort of doubt are totally clear in the text but which nevertheless are the best version of the rules as I see them. They might assign competency to the thief such that they succeed on all basic applications of the skill and only need to roll sometimes, or emphasize the near-supernatural nature of even a level 1 apprentice. Even in this best-articulated framework, it can be tricky to determine how to approach a thief-adjacent activity which is attempted both by thieves and members of more square classes. For instance, if the party is climbing a non-sheer surface under time pressure, how should it be run? For this there are many answers.

But it's sort of weird! Sometimes we say "the thief is better than other classes at certain things," make a procedure for how thieves do it, then improvise from that procedure to determine the worse way the fighter does it. But a lot of these activities are pretty common for an adventure! Maybe the basic procedure should be the non-thief one, and thieves can just get some bonus.

I have a way of doing thief skills that entails more "spot rules" for the thief class, but that I argue may be better integrated into the game procedures in general. For each, I looked at the way a non-thief might do them on the OSE SRD, and assigned a bonus that I thought appropriate.

In coming up with a homebrew rule for thief skills, I am following in the footsteps of many. This proposal is untested, but I think it's a viable direction to take.

This could be you!

* Climb sheer surfaces (CS): A dexterity ability check is required for each 100’ to be climbed, made with a +4 bonus if the climb is any easier than sheer. If the roll fails, the thief falls at the halfway point, suffering falling damage.

[Notes: while ability checks are an optional rule in OSE, the procedure for climbing does in fact call for one, so I thought it would be appropriate to do so here as well.]

* Find or remove treasure traps (TR): When actively searching for traps, the trap’s activation chance is reduced by 1, even reducing traps that always activate to a 5-in-6 chance. An actively searching thief notices when a trap would have triggered.

* Hear noise (HN): In a quiet environment (e.g. not in combat), a thief may attempt to listen at a door or to hear the sounds of something (e.g. a wandering monster) approaching, with pinpoint accuracy on a 2-in-6 chance.

[Notes: this matches the halfling class ability.]

* Hide in shadows (HS): When not directly illuminated, you can remain motionless. No one who knows where you are can detect you from more than 5 feet away until you move or speak.

[Note: this one required more direct innovation. The ability to be unseen as long as one is completely still has come up in several GLoG games, and always requires more creativitiy than one might expect.] 

* Move silently (MS): A thief moving carefully alone gets +2 to their encounter surprise chances. Groups composed entirely of thieves get the same bonus.

* Open locks (OL): Requires thieves’ tools. The thief may make an Open Stuck Doors check on a lock, modified by dex instead of str. If used on a locked door, it does not eliminate the chance of surprise. A thief can only try this once per lock per level.

* Pick pockets (PP): Used against an unaware or friendly target. Make an attack roll, using the +4 backstab bonus if the target is unaware. On a hit, instead of damage take an object that would be feasible to steal, up to a sheathed weapon or worn bracelet. If a particular item is known, the thief can take it. Otherwise, the DM selects a likely object or rolls on a table, such as this:

1. 1d10 silver coins
2. letter from an associate or family member
3. knife
4. Tot of wine or potion
5. ration appropriate to station and climate
6. rat (roll reaction)

[Note: obviously this one also required innovation. Really, how often do PCs pick pockets? It's a high-risk gambit that often has a high penalty for failure, and most foes either carry nothing interesting or are about to die anyway.]