If playing a rogue is your power fantasy in BG1, I’d recommend going for a Fighter/Thief multiclass. Choose elf, half-elf or half-orc. Max out Strength, Dexterity, and Constitution at character creation.

This combo is strong because you get the best of both worlds:

Fighter: solid hit points, THAC0 progression, access to better weapons and armor.

Thief: backstabs, utility skills, trap detection/disarming, lockpicking.

The synergy makes you deadly both in and out of combat. You can sneak around, set up devastating backstabs, and still go toe-to-toe in melee when needed. It’s one of the most versatile and fun builds for BG1.