Robbery (sometimes referred to as an aggravated form of theft or larceny as it implies the use of force) usually atttracts a greater punishment in the criminal codes where it is accompanied by the use or presence of a dangerous weapon. Most criminal codes specifically define this form of aggravated robbery as distinct from robbery.
For example, the 2008 version of the Illinois Criminal Code 1961 defines robbery at section §18-1 and then adds this offence, which carries a greater sentence:
"A person commits armed robbery when he or she violates §18‑1 and (1) he or she carries on or about his or her person or is otherwise armed with a dangerous weapon other than a firearm; or (2) he or she carries on or about his or her person or is otherwise armed with a firearm; or (3) he or she, during the commission of the offense, personally discharges a firearm; or (4) he or she, during the commission of the offense, personally discharges a firearm that proximately causes great bodily harm, permanent disability, permanent disfigurement, or death to another person.
REFERENCES:
Illinois Criminal Code 1961, 720 ILCS 5