Caesar's Legion uses two forms of currency which were also used in Roman times. They are minted by the Legion from scavenged silver and gold, with 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.
The denarius (silver), which bears an image of a younger Caesar on the obverse and Caesar, Joshua Graham and Bill Calhoun on the reverse. The inscriptions are in Latin, "Caesar Dictator" meaning "Dictator Caesar" or "Absolute Ruler 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 Grand Canyon tribes.
Legion Denarius, mangled - A variant that can be found on the bodies of enemies injured with the 12 gauge coin shot crafted ammunition. Despite the description, it appears identical to the normal Legion Denarius but is worth only half the value, at 2 caps instead of 4.
Non-currency item versions of Legion Denarius exist within the game files of Fallout: New Vegas, but were not included in the final game. These versions are identical to the standard currency but weighted at a rate of 0.02 per coin, or 125 coins per weight unit instead of having null weight. Due to being weighted, this variant functions as a miscellaneous item rather than a currency, and thus its trade value is affected by the Courier's Barter skill.
The Denarius is one of two forms of currency used by Caesar's Legion, the other being the Legion Aureus. Of the two, the Denarius is both the least valuable and the most commonly found.
As with any form of currency in Fallout: New Vegas, Legion Denarius is not affected by the player character's Barter skill. The currency will always be valued at 4 caps, regardless of whether the player character is buying or selling.
The Legion Denarius does not show up when the items are sorted into item type on the container menu. It only shows up when the items are sorted back alphabetically on the container menu.
Both the denarius and aureus were forms of Roman currency used during the time of the Roman Empire, with the aureus being valued at 25 silver denarii.
When post-endgame play for Fallout: New Vegas was being considered, J.E. Sawyer intended for the Legion to mint a commemorative double aureus featuring a depiction of a conquered General Lee Oliver on the front and a symbolism for the Courier. The idea for the coin is inspired by the Vercingetorix denarii minted by Julius Caesar after his victory over the Gauls.
↑Rose of Sharon Cassidy: "Some caravans deal with the Legion now because the security. If towns could get the same protection? A lot more tempting than you'd think. Bunch of people would be willing to side with the Legion to not have to worry about Fiends and Boomers and Powder Ganger attacks." (Rose of Sharon Cassidy's dialogue)