The best substitute for nutmeg is mace, the red membrane that surrounds nutmeg when harvested. Though it's a bit more delicate in flavor and lacks nutmeg's bittersweetness, mace will work in a pinch.

Cinnamon is brighter, sweeter and less woodsy than nutmeg, but it fills in nicely in smaller amounts. Allspice and garam masala are both reminiscent of several spices, and will also work in place of nutmeg in small amounts.