|This is a lore summary, presenting intradiegetic or in-universe information about the subject. For game characteristics and similar data, consult the table on the right.|
The currency in the Fallout world varies from area to area and even faction to faction.
United States dollars (USD) were the pre-War currency of the United States of America. The inflation presumably caused by the Resource Wars was severe, leaving banknotes as the primary medium of exchange. Although the Great War eliminated the United States and its economy, reducing stacks of green bills to little more than collector's items and scrap parchment, certain pre-War devices continue to recognize them as valid currency. These are typically limited to areas like the Sierra Madre casino or the Nuka-World amusement park.
Bottle caps are one of the symbols of the post-nuclear economy. While widely available, they are also in limited supply, as the technology necessary to manufacture them was largely lost to time and the Great War, and difficult to produce by hand. The paint used, machining, and metal type all have to be very specific in order for a bottle cap to be genuine.
These factors led to their adoption by Hub merchants in New California as common unit of exchange, backed by water. The adoption took place rapidly, as within ten years of Hub's founding in 2093, caps became the standard currency of the wasteland. For similar reasons, the merchants in the Capital Wasteland also adopted bottle caps, although it is unknown who backs their value. Near simultaneous with events at the Hub, bottlecaps became the standard currency in Appalachia as well for many of the same reasons. And although humanity was all but wiped out around 2102, many vending machines had been modified to accept caps as tender allowing the bottlecap use as currency without anyone around to actually back it.
In the 23rd century, the venerable western bottle caps were eventually supplanted by minted and printed currency, New California Republic (NCR) dollars, backed by gold, rather than water. However, during the Brotherhood War the Republic's gold reserves were destroyed by Brotherhood raids to the point where new gold coins could not be minted and paper money could not be properly backed with gold. NCR citizens panicked and rushed to reclaim the listed face value of currency from NCR's remaining gold reserves. Since the NCR was unable to realize these withdrawals, particularly towards the frontier, faith in their currency considerably dropped. To protect against actual economic collapse, the NCR government abandoned the gold standard and established fiat currency, not payable in specie. Since then many wastelanders lost faith in it as a medium of worth, both as a result of it not being backed by anything but the government's word and the inevitable inflation. In response to the loss of faith, merchant consortiums of the Hub established their own currency, the veritable bottle cap, backing it with water (exchanging a standardized measure of water for caps).
The actual process was very deliberate. The merchants conspired to reintroduce the bottle cap as a currency, out of frustration at NCR's ineptitude in handling the currency crisis. Furthermore, since Hub bridges the NCR core region with the Mojave and lands beyond, the cap was meant to bridge the gap between NCR and Legion territories by providing a neutral form of money. In the time leading up to the introduction the merchants laid the foundations for bottle caps as a currency, establishing control of or destroying facilities that could fashion new bottle caps and seizing excessively large caches of old bottle caps (smaller ones in private hands were left alone, as their owners would readily embrace the returning bottle cap).
To protect their monopoly on the currency, Republic merchant companies, particularly the Crimson Caravan Company, seek to control all bottle cap production and ensure that no one can mass produce them and inflate the currency. Controlling bottle cap presses also allows them to replace worn out and damaged bottle caps, keeping the pool of currency stable. Due to the challenges of the bottle cap production process, small scale counterfeiting is ignored, as it's impossible to manufacture enough caps by hand to truly upset the balance.
Bottle caps, NCR dollars and Legion currency are all considered legal tender by the various caravan companies and on the New Vegas Strip. Mojave merchants also accept nonstandard variants, such as Sunset Sarsaparilla bottle caps.
The NCR introduced its own money around the turn of the 22nd century and initially it relied on coins minted from gold. By 2241, the economy of NCR dominated the West Coast and coins became universal currency, used by the three regional powers: NCR, Vault City and New Reno. During this time bottle caps had become worthless in these regions.
During the conflict with the Brotherhood the Republic's gold reserves were destroyed by Brotherhood raids to the point where new gold coins could not be minted and paper money could not be properly backed with gold. NCR citizens panicked and rushed to reclaim the listed face value of currency from NCR's remaining gold reserves. Since the NCR was unable to realize these withdrawals, particularly towards the frontier, faith in their currency considerably dropped. To protect against actual economic collapse, the NCR government abandoned the gold standard and established fiat currency, not payable in specie. Since then many wastelanders lost faith in it as a medium of worth, both as a result of it not being backed by anything but the government's word and the inevitable inflation. In response to the loss of faith, merchant consortiums of the Hub re-established their own currency, the veritable bottle cap, backing it with water (exchanging a standardized measure of water for caps). 
By 2281, the NCR dollar is valued at about 40% of a water-backed cap and only 10% of a silver Legion denarius. In the Mojave Wasteland, these notes can be seen in the $5, $20, and $100 denominations. The notes are issued by the Republic Reserve Bank located in Angel's Boneyard. In 2281, the current Treasurer of the Republic and head of the NCR Treasury is John Michael Henderton; his signature can be found on the front face of all NCR notes found in the Mojave Wasteland.
Caesar's Legion uses two types of coinage, the denarius and aureus, as their main form of currency. They are presumably named after the Roman coins of the same names. 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, even from NCR merchants, owing to the precious metals the denarius and aureus are minted from. 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.
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 "For the eternity of the empire" on the front and "Pax Per Bellum" meaning "Peace through War" on the back.
While not technical currency, casino chips are used by the casinos of New Vegas and its surrounding environment. Casino chips can be bought from vendors inside the casino and used to play games such as blackjack, roulette or slots. Depending on the outcome of these games, gamblers can gain or lose chips which can then be redeemed at their respective casino for bottle caps, NCR dollars or Legion coins.
List of Casino chips
- Atomic Wrangler chips
- Gomorrah chips
- Sierra Madre chips
- The Tops chips
- Ultra-Luxe chips
- Vikki & Vance chips
|The following is based on Fallout Tactics and some details might contradict canon.|
Brotherhood scrip is legal tender within the Brotherhood of Steel of the Midwest, for trading within the organization. The currency itself bases on printed banknotes, issued by the Brotherhood Treasury.
|The following is based on Fallout Tactics and some details might contradict canon.|
Ring pulls are used as currency by people in the vicinity of Chicago. They are pull-tabs from soda cans. Ring pulls can be found all over the settlements in early missions and traders will accept them. There are usually some outsider traders in Brotherhood bases who will accept ring pulls as well.
Behind the scenes
Fallout: New Vegas
Unlike Pre-War money, Legion Money and NCR Money are not affected by the Barter skill. I.e. $5 NCR is always worth 2 caps and a Legion Aureus is always worth 100 caps. I don't think I ever suggested some Bardi-esque currency inflation/speculation gameplay, just that the different factions had different forms of currency and that each was "backed" differently: caps are water-backed by Hub merchants due to the decline of the inflated NCR fiat currency and Legion money is not "backed" at all, but of value due to the use of commodity rare metals. The currencies are there for flavor and to reflect something larger about the societies that use them.”— J.E. Sawyer