Legion currency

 or Legion money is a type of currency in Fallout: New Vegas.

Background
Caesar's Legion uses two old forms of currency which were also used in Roman times. They are minted by the Legion in the form of silver and gold coins, each coin bearing the profile of Caesar. Despite Caesar's poor relations with the other factions in New Vegas, Legion currency is still accepted as payment in the Mojave Wasteland, owing to the high level of trade with the Legion and the safety of its territory for caravans. The exchange rate is 4 bottle caps to 1 Denarius, and 100 bottle caps to 1 Aureus.

Legion Denarius


 The Denarius (silver), which bears an image of a younger Caesar on the obverse and Caesar, Joshua Graham and Calhoun on the reverse. The inscriptions are in Latin, "Caesar Dictator" meaning "Dictator Caesar" on the front and "Magnum Chasma" meaning "Great Abyss" or "Great Fissure" on the back, referring to the Grand Canyon. The symbolism is simple - the denarius commemorates young Caesar's journey to the Canyon and his first victories as a dictator of the tribes. 
 * For the mangled version found in Fallout: New Vegas, see: Legion Denarius, mangled.

Legion Aureus


 The Aureus (gold), which bears the portrait of the older Caesar on one side and the symbol of the 10th Legion (the bull) on the other. The inscriptions are in Latin, "Aeternit Imperi" meaning "Eternal Authority" on the front and "Pax Per Bellum" meaning "Peace through War" on the back. 

Behind the scenes
 Both the denarius and aureus were a form of Roman currency used during the time of the Roman Empire, with the aureus being valued at 25 silver denarii.