If you play a resource-intensive game on a slow laptop, will it wear out faster?

Uh, well it's ill-advised just b/c your experience will probably be shit. However if it's a newer i3 chip with the graphics built onto the chip it probably should be okay as long as you keep it on low settings. It's still a stupid idea since your machine is obviously not designed to play such a game. Quite honestly the only intel graphics you should ever game with is Intel HD 4000 graphics and even those are pretty shit. The next generation of Intel i5 and i7 chips along with Intel HD 4000 graphics will actually be tolerable but those won't be available until probably Winter 2013 so *shrug*. Basically get a laptop with discrete graphics (nvidia or amd whatever) and at least an i5 processor or make an actual decent gaming PC.

Jam it back in, in the dark.