RSA 636:1: Robbery.

I. A person commits the offense of robbery if, in the course of committing a theft, he:

(a) Uses physical force on the person of another and such person is aware of such force; or

(b) Threatens another with or purposely puts him in fear of immediate use of physical force.

II. An act shall be deemed "in the course of committing a theft" if it occurs in an attempt to commit theft, in an effort to retain the stolen property immediately after its taking, or in immediate flight after the attempt or commission.

III. Robbery is a class B felony, except that if the defendant:

(a) Was actually armed with a deadly weapon; or

(b) Reasonably appeared to the victim to be armed with a deadly weapon; or

(c) Inflicted or attempted to inflict death or serious injury on the person of another,

the offense is a class A felony, except that if the defendant was actually armed with a deadly weapon, and the deadly weapon was a firearm, he shall be sentenced in accordance with RSA 651:2, II-g.