I was too busy to participate in this discussion when it happened, but I’d like to suggest another way to reconsider Thief-type classes. I’d start with this vision of the BX Thief:
The Thief is a 3rd level Magic User that trades their limitations on number of spells for reduced scope and a chance of failure. The high chance of failure at early levels is compensated for by improved melee abilities. The chance of failure diminishes as the Thief gains levels, putting the character on a trajectory to perform mundane, sometimes slower versions of a subset of first and second level spells at will.
The Thief knocks-off magic missile with missile weapons; knock with pick locks; locate object with find traps; levitation with climb walls; invisibility with hide in shadows; read languages with… you get the idea.
My reboot of the Thief would be a class that crystallizes this vision: A Thief derivative whose skills are rearranged so that those mocking first level spells are easier than those mocking second, with an escalating bonus to hear noise and missile damage as they increase in level. And possibly some sapping skill (both kinds!). This class is a roguish dabbler in sleights of hand, tinkering, archery, and minor alchemies and biologies… a crypto-medieval Indiana Jones, without the respectability of university backing. Not a pickpocket, but a gray-market businessman with insight into fringe sciences and less-than-respectable studies.
But that’s another post. First, tell me where my vision of the BX Thief is inaccurate.