Here's a way to deal with repeated thieving. Let's just say add a cumulative penalty of -25% (or -33%) for weight and gold value for each theft after the first. So if you can steal 100 and 100 the first time, then 67/67 the second time, 33/33 the third time, and then add it would be 0/0 the fourth time, but let's boost it up to 10/10.
That would be a way to limit the amount of thieving you can do without nerfing it into the ground for one-thief-only parties. If you want to make 4-thief parties, then go ahead.
To reduce reward for tasks that require more investment is the definition of Anti-fun that has been the taboo of modern gaming design, this game is no exception. The principle of losses is that every deduction will have twice as much impact compared to what it is seen and this kind of change will hurt the game way more than it helps especially with the whole "You can be anything" approach of this game.
When a mechanic is as simple as this game thievery, you can't just nerf it directly. You have to adds complexity or depth to it instead in order to create more choices and way to adjust the mechanic.
Instead of trying to harm people for stealing multiple time, make it harder to steal multiple time with non-invested characters so that players have to explore different options if they still want to play multi-steal.
Zaleskar is an example of what it's like to be so hard to steal it's almost not worth the investment to hunt for the gears because of his 16 wits and level 2 base thievery, forcing most people to somehow find 3 gears before stealing from him, which is very difficult unless you're really lucky.
-When stealing is done, temporarily increase the wits of NPCs by 1 or 2 points with same amount of initiative reduction so nothing changes combat-wise. Call it something like "Awareness" and make it last like 99 turns so you have to go do something instead for the awareness to drop.
Something as simple as this will prevent people from being able to steal multiple time in one go as it's no longer possible to just use the bed roll to bump the finesse above the NPC's Wit for non-thief characters to bypass the extra thievery requirement.
- Increase the effect of having a massive gap in your Finesse and opponent Wit. Every 5 differences will add 1 to Thievery requirement. Zaleskar will end up requiring 4 thievery instead of 3 for people who invest absolutely nothing into Finesse and just 2 rings + 1 necklaces won't be enough. This will also forces people to explore more options if they still want to steal with mages/warrior and start using more buffs and even stat potions just to be able to bring down the thievery requirement level to the point it can still be reached.
