One old quarter = 10 tokens, or 100 aluminum can tops
One token = 10 aluminum can tops
I could see tokens and aluminum can top being switched though
My love of Fallout aside, if it was in North America, i'd set the currency as the Dollar, paid out in gold and silver coins, or Ring tabs. On a side note, I have a method of converting TU into a dollar figure in that thread I made, along with other stuff if anyone's intrested...
alternately, you could use something like paper currency, or even something like bottlecaps or ring-pulls, but there are some definite problems with those in terms of currency. in order for those things to have value, there has to be some entity that will accept it as valid currency, and it's value would be based on the value of the assets that said entity has available.
for example, if the local trade post has 100 TUs worth of stuff in it, and issues 200 trade credits (each of equal value), then each trade credit can't have a real value of more than .5 TU (though it could potentially have a perceived value of higher than that)
for something like ring-pulls or bottle caps, this poses a huge problem; you could walk out into the middle of nowhere and get a bunch of them without having actually received them from the central authority. which means that nobody actually even knows how much 1 of them is worth. works fine as long as you're not too worried about suspension of disbelief i guess, but otherwise it can be a problem.
Pennies = ~$1-5
Nickels = ~$20
Dimes = ~$50
Quarters = ~$100
And damn, in that setting, it was unlikely if you ever got anything higher then that, else your own mother would shank you in your sleep.
OnButterflyWings also has a good suggestion.
My question, is what made Gold so valuable? It seems like a strange question to ask, mainly because Gold has always been valuable, but why?
in terms of practical uses, the only one i know of is that gold is apparently a really good conductor of electricity. and conveniently, is also quite ductile, iirc... which would make it really useful for electrical wire.
so, obviously the atlantean empire needed a lot of gold for electrical wiring in all their techno-wizardry devices ;) :P
I can see why it was used.
I think I'm going to use scrap metal as currency. Basically they'd be quite small pieces but be completely random in shape.
Aluminium, Steel, Copper and Gold I think. I will post when I work out values.
We've discussed the possibility that our spent casings could be worth something as a form of currency, with a live bullet being worth more than the casing. Though we all agree that it might lend even reason to conserving ammo.
Individual units are rounds. Groups are mags, with 10 being a short mag and 30 being a long mag. 100 rounds are a belt, and 200's a long belt. The standards are 9mm and 5.56mm with local fluctuations depending on the type of firearms being used.
there is, however, a thread about converting TU to money linked in an earlier post, and i think there might be one for TU ==> wealth check (or vice versa) around as well.
so basicaly I would go with person A has 10 bags of corn but is looking for steak. person B owns a few cows but is looking for eggs and person C owns 20 chickens but doesn't have any food for them. so A would swap some corn for a few of C's chickens or maybe his eggs then swap the eggs/chickens with B for a cow.
basically how trade was mostly conducted in the neolithic -> middle ages
just imagine a world where the super rich enjoy weekly baths and all the water they can drink while the poor die of thirst or try to hijack water shipments protected by armed guards.
the PCs could play a kind of robin hood figure stealing water (or distalition equipment) from the rich and giving it to the poor or they could be one of teh guards charged with defending the water shipments and water tanks from the criminal elements of society (allows jakboot wearing head stomping campaign)
For FX items, how about making converting purchase DC into the Diplomacy DC to persuade whoever's got the item to part with it at all, and then have the actual repayment be more of an adventure-hook?
Or, for a more cyberpunk apocalypse, have purchase DCs and the wealth system still in effect, but usable only on the 'net and in deals with god-like AIs.
I just had a thought about this topic earlier today and was thinking why not make water the standard currancy good for spocolapses where pure water is hard to find due to polution or some other cause, where only the rich have the equipment to pump water from the deep underground watertables or to purify poluted water. while the poor have to work for the rich just to get enough water to survive the day. (could be a good setting for an oppressive goverment, where the rich hold the lives of everyone under them in their hands)
just imagine a world where the super rich enjoy weekly baths and all the water they can drink while the poor die of thirst or try to hijack water shipments protected by armed guards.
the PCs could play a kind of robin hood figure stealing water (or distalition equipment) from the rich and giving it to the poor or they could be one of teh guards charged with defending the water shipments and water tanks from the criminal elements of society (allows jakboot wearing head stomping campaign)
I think Tank Girl when you mention that.
1) it's heavy. this is largely related to point number
2) you need a reasonably large volume of it to have any value. that is, 1 mL of water is not terribly useful from a survival standpoint. if you're going to buy something expensive, you'll need a large water tank... which will most likely have value in and of itself.
3) it's really, *really* hard to regulate water. it can be obtained pretty easily, it's value is going to be based on whether or not it's drinkable... and undrinkable water is not necessarily visibly different from drinkable water.
4) it's a necessity of life. you have to use it up. you would literally be drinking your money away if water was money =P
now, that being said, it is entirely reasonable that drinkable water would have value, but to use it as the main form of currency? not so likely.
2) you need a reasonably large volume of it to have any value. that is, 1 mL of water is not terribly useful from a survival standpoint. if you're going to buy something expensive, you'll need a large water tank... which will most likely have value in and of itself.
well that would depend on the value you place on the water. for example if the world was so polluted that drinkable water was only obtainable useing highly advanced technology that only a few people had access to then drinking water would become more expensive than gold. it would basically replace crude oil in todays financial market.
in such a world people could spend all day working for a single bottle of water, basically it's a monopoly, who ever controls the water processing plants controls the population and in extent the world
3) it's really, *really* hard to regulate water. it can be obtained pretty easily, it's value is going to be based on whether or not it's drinkable... and undrinkable water is not necessarily visibly different from drinkable water.
like I said above using water would only be useful in a world that was so polluted that even rain water was toxic. as such people would probably have some means of testing water purity (maybe a some form of prod for those that can afford or build such things)
4) it's a necessity of life. you have to use it up. you would literally be drinking your money away if water was money =P
well there's the thing that gives it value. would crude oil have any value if we didn't depend on cars, planes and plastics? with that line of reasoning wouldn't drinkable water become a valued commodity in a world so polluted that even breathing the air could be bad for your health?
and if you don't like the idea of dealing with huge tanks of water why not use water chips. simple credit card like devices that allow you to buy water from the local pump based on what work you have done. these "water chips" could then be traded for other things. after all isn't that what money is today (read a bank note, it says "I promise to pay the barer on demand the sum of £XXX" or something close to it) basically money these days represents a portion of gold held in the bank's vaults the paper bank note has no real value, but it's a deed of ownership for a small amount of gold.
basically it means that one could trade in say 20 litres of water they happen to find for a brand new car simply becuse of the value placed on water as a means of survival (after all isn't that what you need money for mostly, to survive. everything else is secondary)
plus giving value to something as common as water could give the game that feeling of desperation. the world is so screwed up that people will kill each other for a cup of water. not to mention the plot points (evil corperations sucking water out of helpless victims leaving only dried husks, terrorists poinsoning the water supply) and you could add the enviromental factors to the game (polluted air making breathing dificult without some form of rebreather or filter, acid rain capable of burning the skin) then there's the whole socio-political situation (jackboot wearing goverment thugs beating people for spilling a glass of water, milatary personal guarding water trucks and shooting people who try begging for a cup of water) and so on.
granted it may not sound like an ideal form of currancy but if you think about it which would have more value in a post apocalyptical world, gold, diamonds and rubies or simple things like food and water?
think about it if you lived in a post apoclyptical world and I gave you a choice between an once of gold and a bottle of water for doing a chore for me which would you take? which would have the most value in a world where much of the infrastructure had collapsed? which would have the most value in a world where there were no banks, where fashion and one's personal appearience were secondary to the survival of the species?
Gold's pretty heavy too, which is part of why people don't trade with actual bars of gold. Long ago, goldsmiths and pawnbrokers started to hand out pieces of paper that could be exchanged for gold, and people traded with those pieces of paper instead.
Similarly, an aluminum pop-tab is associated with a particular volume of water, but weighs enormously less than that much water, and is difficult to counterfeit.
now then, as far as explaining further why water doesn't make good currency, allow me to clarify. you don't want to use water for currency because it is needed for other things. the people who control the money are going to want to have something that they can hoard, and water is not that something... it's something they have to give out, because if they don't, they have nobody to buy stuff from with their enormous wealth.
for lack of a better way to put it, you don't want to use water as wealth because it *has* to be spent. you can't just set it aside and choose not to use it. and holding it from the general public just means that the general public will brutally murder you or, if your guards can stop that, your guards are going to become corrupt and start selling off your water when you aren't looking, because they don't want to watch their friends die. unless you make water cheap enough that *everyone* can afford it, then you're going to end up with everyone who can't afford it dying, which reduces the demand for your water, which means that if you want to use water as your source of money than everyone must either have it or be dead already, which means no poor people with nothing in the post-apocalypse world.
now, water can certainly be expensive, but it can't be *the* form of currency. it could certainly be a tradable commodity, but by it's nature, the greater the demand for it, the more people will die for not being able to buy it, which lessens demand for it.
so sure, you could barter with water (and you could still have all those situations you mentioned if you did) but you wouldn't want to use water as the main form of currency. not with the kind of quantity that is required for daily life. farmers would have to be obscenely rich in order to survive, for example, if your water was money. water can be rare, but you can't make it impossible for people to get, and you want to be able to deny some people money if you're looking for low-resource apocalypse situations.
but the main problem with that is for water to be so valuable, you would need to have a continent-wide control of water... otherwise you go someplace where it's just the normal thing, and someone brings in a few mule-loads and they're set for life. or, if it's hard to bring to you, everyone just leaves, and you're sitting there on a pile of worthless water because there's no one who needs to drink it. then wherever everyone is going becomes strong and wealthy, and comes in to kill you and take your water, because now they need your resources to support the population you just drove away ;)
so yeah, i could get behind water having value, even being expensive. but being money? nope. oil may be valuable, but it isn't money. i can't go to the grocery store and buy a loaf of bread with a cup of gasoline.
as far as money being backed by gold... actually, no. it's not really backed by anything these days, other than the fact that someone else wants it just because it has perceived value.
imo, if you're going to have currency, it's going to have to be on a very local level, and will either have to be based on something that has value but is not a necessity (for example, useful metals like iron) or it will only be of value within a certain area (wherever the issuing entity has power and places close enough to be able to trade with that area)
as far as money being backed by gold... actually, no. it's not really backed by anything these days, other than the fact that someone else wants it just because it has perceived value.
The US dollar is not backed by "nothing." It is backed by the full faith and credit of the government of the United States. If there were no rich, widely-respected governments (and there'd better not be, this is the apocalypse after all), people would revert to currency backed by valuable substances.
You say that pop-tabs are too cheap, and then you twirl right around and say that without them water would be too expensive. Consider this scenario:
There are few, if any natural sources of potable water. The Baron has a water-treatment plant, which produces more potable water per day than he could possibly need. The area surrounding The Baron's fortress is a ruined city, within which a seemingly vast supply of pop-tabs can be found, but pop tabs are small, and it's a big area to search, so finding them is non-trivial.
The Baron decrees that anyone can bring pop-tabs to his fortress and exchange them for a soda-can-full of water per tab. Shortly thereafter, all the easy-to-find pop-tabs are found, and turned in to the Baron. Some people continue to find pop-tabs at a steady enough rate to keep themselves hydrated, or find clever ways import them from distant lands.
The Baron, meanwhile, still has more water than he knows what to do with, and an enormous supply of pop-tabs, growing all the time. So, when he wants something (the people who scavenge for pop-tabs sometimes find useful artifacts, and importers use their connections to acquire even more astonishing treasures; mercenaries also do needful work), he can pay for it in pop-tabs. The Baron has no actual need for pop-tabs, so they're worthless to him; everyone else needs water, and pop-tabs are like water that never goes stale.
By instituting pop-tab/water exchange, The Baron has:
1. Greatly expanded his ability to store wealth (since he can store thousands of pop-tabs in a bucket that would hold only a day or two of water, or even skip buckets entirely and just pile them on the floor)
2 Made mercenaries more willing to accept his payments (since he can give them a year's worth of supplies in a form they can actually carry)
3. Increased the supply of available artifacts from the surrounding ruins, at no risk to himself (since the pop-tab-scavenging industry drives exploration, and motivates successful scavengers to stay and trade near his fortress)
4. There's no revolution in a water-monopoly empire.
If you had your own abundant-but-defensible supply of water, and heard about The Baron, what would you think of trading a traveller some of your excess in exchange for pop-tabs?
the corperations battle among themselves to control the remaining resources and the population (resulting in one or two global powers).
the corperate goverments start laying down laws against people hording water. making out that those who operate illegal pumps are evil and by turning them in they get a hefty supply of water (which they can buy at any corperate water pump). civilian population is allowed x amout of water a day (basically enough to survive) extra water is given to those that work the hardest. those who fail to work or who work against the corperation get their water rations cut or stopped.
now basically every person has to have a transponder chip implanted in their hand or is issued with a "water card" (depends on how evil you want to goverment to be as the chip can be used for tracking ect) this water chip/card allows one to buy water to survive but also allows them to transfur water credits to other people so basically the water acts as the currency but you remove the need to transport huge quantities. and with a global totalitarian goverment making sure no one produces illegal water the goverment is safe from riots or a coup. granted there would still be the underground societies trying to sell water to people and thus make themselves rich in the process. or maybe even trying to over throw the goverment and release the water to the general public.
people get mugged on the street not for their jewelery or the wallets but for the bottle of water they just got from the pump.
basically water is still the basic unit of currency but it's not being transfured directly.
or if thet doesn't tickle your fancy you could always go the system shock 2 approach and use nanites (tiny robots) which when used with special computers (replicators) they produce what you require out of a stock of stored materials. you could also add a utilatarian function to them such as repairing equipment and so forth. though this would only be useable if the technology level exsits to produce such machines.
or you could go with a total electronic form of currency where everyone is issued a credit card and you can do away with the whole X comodity is valuble. y comodity is not valuble.
or if the society becomes totally decadant then you could make anything that is attractive valuble (cut glass, carved wood, poetry, ect) so that artisans and entertains rule the world and those that keep everything running (engineeres, builders) are at the bottom of the ladder. could make for a more visually pleasing post apocolyptical world (think of the renasaunt(sp) period).
it really depends on how you want your world to be. a bleak dog eat dog survival at all costs world where water is everything. (mad max, tommorow's end, tank girl)
a dystopian world where electronic survalance is parimount and your every transaction is recorded on a massive centeral computer every time you use your credit card (think deus ex, blade runner)
a techno paridise where computers run everything. (makes for good rogue AI games) where fashions change every week. people are coercied into buying new things every day with their hard earned nonbots.
or a space opera style game where everything is made to spicific artistic standards and anything that doesn't meet with said standards is removed (be it buildings, objects or people). maybe people have reverted to carrying rapiers and walk around dressed in period fashion (could make for intresting gameplay) good old steel blades go next to monomolecular blades and energy weapons. space craft could be fashioned to look like giant flying sailing ships all to match the people's value for art and fashion (think faiding suns, deathstalker, the centari from babylon 5)
bottom line is that what ever you decide to use as your currency match it to your setting. for example a technology advanced civilisation wouldn't need water as much as a civilisation on the brink of collapse. so decide on your setting then pick something that the people in that setting would value
now then, carrying on:
none of the proposed examples above are actually using water as currency. sure, the water is the basis of the baron's currency, but people aren't buying things with water, they're buying things with pop can tabs (which, as i said before, strikes me as a really bad idea, but i'll get to that later). furthermore, like i said, that currency only has any value at all within the baron's domain or close enough to it that trade is feasible (taking into consideration that the baron is the only person looney enough to trade a tiny piece of largely useless metal for something which is apparently as valuable as water).
but the problem is that once water is used, it can be recycled. give it a while, and nobody needs the baron's water purifying plant, because heck, they can just distill, boil, and/or chemically treat the water themselves, and a lot of the materials required aren't even all that hard to get. about the only thing i could see the baron even really being able to get a monopoly on water is if he has some way to remove radiation from it, but then again... if everyone is living within an area with irradiated water in large quantities, they're gonna have problems with more than just the water.
anyways, i'm not sure where it is that you're saying i think without pop tabs water would be too expensive. water itself is a poor choice for currency. it's perfectly reasonable as a valued commodity, and i said that. i just think pop-tabs are a poor choice for coin. for one thing, it would be like buying everything in pennies. or, alternately, it would be like having only dollars, and so anything that would cost somewhere between 0-1 dollars is 1 dollar, and so forth. in the event that i was the baron, i would probably mint coins out of clay or something like that, and rather than just handing out water at first for what would be (almost, they can be recycled of course) valueless pop can tabs you could produce ceramic coins (swiped shamelessly from dark sun, for the record). these ceramic coins would equally have their value backed by the water, and more to the point, the baron would be the guy who issues the coins and could get something of value for his water the first time, and could offer either a certain amount of water now or a lesser amount of water redeemable whenever the bearer of one of his coins chooses (which has the advantage that you don't have to try to haul around hundreds of gallons of water to make a large purchase). furthermore, the odds of someone finding a pile of ceramic coins (with the appropriate stamps etc) that the baron did not issue is significantly smaller than the chance of finding a pile of pop can tabs that the baron didn't issue.
of course, now you might have to start worrying about forgery, but there's gonna be a lot fewer people capable of building, from scratch, a mold that will perfectly match the baron's than there are people who can stumble across pop can tabs. furthermore, if the baron were to use a specific clay every time, and that clay was in some way distinctive, that makes it even harder to make fake coins. this would also work with something like plaster, of course, but the most important point is that the coins in question could be made in different denominations, and that they are much, much harder to get ahold of without the baron getting paid something useful. also, the baron can have a reasonable idea of how many of his issued coins are out there at any given time... not so much with pop can tabs. imagine how awkward it could be if someone found a collection of pop can tabs while scavenging that was actually too large for the baron to redeem! at least if someone shows up with a bunch of coins, the baron knows how many coins he issued to begin with, and can plan to always have enough water to cover his debt.
so sure, you could use pop can tabs as currency. but it's just a really substandard idea that isn't likely to work nearly as well as actual printed/minted currency will. now of course, these ceramic coins are just as useless outside the baron's range of influence as any other worthless item, which is why i still support the use of barter for most purposes. unless there is a central government, currency in general doesn't work.
so i'm not saying you couldn't buy stuff with water, and i'm not saying you couldn't buy stuff with currency backed by water... i'm saying that water in and of itself is a poor form of currency, and that there are other commonly available vastly superior forms of currency out there that would be much more likely to be used.
If someone shows up with three bazillion pop-tabs, and the Baron has only two bazillion cansful of water on hand, yes, that would be something of a crisis. However, the Baron's original problem was that he had abundant water-production capacity and nothing to do with it, so he should be quite happy to redeem maybe half of the "coin" immediately, then invite the wealthy traveller to stick around for a few days and enjoy the hospitality while machinery gets dialed back up to capacity (for the first time in years) to refill the tanks. I mean, what's the point of all that delicious water if you haven't got the time to savor it?
If the traveller insists on being paid in full, immediately, and wants to leave in a wild hurry... well, that's an adventure hook if ever I saw one. The Baron hires the PCs to investigate and/or stall for time.
The problem with ceramic coins is, they really aren't that hard to counterfeit. Molding clay is neolithic technology, and it's easy enough, with the right skills, to start with one coin and end with hundreds, each one cosmetically indistinguishable from the first. Might be possible to tell the difference with a magnifying glass, but what the hell kind of apocalypse has ordinary people running around with high-quality optics? Also, ceramic tends to erode and shatter.
Pop-tabs, on the other hand, can't be duplicated with anything less than an electrolytic Bauxite smelter, a rolling mill to forge sheet metal, and a press to cut and shape the individual tabs. Anyone who's got all that infrastructure could probably just cut a deal with the Baron directly, rather than trying to undercut currency.
The great thing about water is, everyone needs a certain amount per day, and it's so heavy and fluid that it's impractical to transport in quantity. Both of these would tend to keep the day-to-day demand for water relatively constant, so as long as the Baron can meet the local demand with a bit of excess capacity left over, and has a buffer big enough to absorb the occasional out-of-town order, there's very little risk of a 'bank run.'
Also, the Baron can and will make efforts to attract and befriend the kinds of people who would be willing to kill for water, and make it clear to them that anyone who endangers the pop-tab-exchange system is endangering the whole water supply. Go ahead, kill the Baron and take his stuff, nobody's particularly loyal to the figurehead... but if you mess with the exchange rate, there are a lot of big, dangerous people, impoverished by your actions, who would like to speak to you. And by "speak," I mean "inflict grievous harm."
but the problem is that once water is used, it can be recycled. give it a while, and nobody needs the baron's water purifying plant, because heck, they can just distill, boil, and/or chemically treat the water themselves, and a lot of the materials required aren't even all that hard to get. about the only thing i could see the baron even really being able to get a monopoly on water is if he has some way to remove radiation from it, but then again... if everyone is living within an area with irradiated water in large quantities, they're gonna have problems with more than just the water.
that's assuming that distilition and filtration equipment is legal. sure people can still rig up stills with a couple of buckets and some pipes but that doesn't mean that goverment stormtrooper's won't bust down their door and kill everyone inside and steal their water.
next there's the problem with how much water can be recycled from a human body. only a small amout of water is obtainable from urine as most is lost in sweat and through breathing, just breath on a cold peice of glass and see how much water you get then multiply that by how many times you breath per a day (that's a lot of water you lose per a day) meaning that the person controling the water still has power.
just as a side note as for removing radation from contaminated water an activated charcoal filter would romove most of the radation. (at least alpha and beta emmiters) in fact a simple paper filter would romove a large portion of alpha emiting radation
(as a aditional note alpha and beta radation are the most deadly inside the body as gamma can pass out of the body while alpha and beta bounce about inside the body)
to further remove radation it can be done with something as simple as a magnetic field a simple magnet dangled next to a water pipe would draw out much of the radation except gamma emmiters (alpha and beta radation is positivly and negitivly charged accordingly) passing the water through an ionised/staticly charged filter would do the job.
basically no matter how polluted water is with the right technology it can be cleared. the problem is getting that technology. the person who controls that technology controls the water and in extention controls the people.
to show how valuble water is if I owned ll the water in the world how much would any of you pay for just one glass so you can survive until tomorrow?
no do you think it's not a good means of curency (just think of the film water world they actually used dirt to as money)
what i suggest is if you don't like the idea of water as currency then use something that would be valuble to the campaign setting. or you could go really indepth and use diffrent means of currency for diffrent towns and cities. for example town A in the desert could consider water the most valuble thing in the world while town B which sits on the shores of a huge lake could consider building materials as valuble.
If the Baron is selling water for a pop-tab per 12 fluid ounces, and you've got your own private atmospheric still that can just barely produce more than you yourself need to survive, what're you going to do? Give your surplus away for free, undercutting (and quite possibly enraging) the Baron and his mercenary freinds, while gaining nothing for yourself? Or are you going to sell what you don't need at the market price, knowing that if you ever need more than you can produce, you can cash in that handful of pop-tabs for more water than you could possibly carry?
and i still say you aren't using water as currency, you're using it as something to back the currency. the currency is pop can tabs, not water. notwithstanding the pop can tabs have a specific value defined in terms of a volume of water, they are not actually water.
It would be viable because the tokens are otherwise worthless, small, light weight, long lasting and difficult to devalue; while the base commodity is valuable, bulky, heavy and naturally deteriorates (through both use and storage).
The water purification plant/pumping station acts as a self renewing bank.
In my game which is an odd hybrid of post apocalypse and cyberpunk- silver is the physical transferable currency while credit is used for most transactions. To exchange between the two is expensive because of the banker's share and often heavy taxes that the local government adds. Since the infrastructure to transport money (credit) doesn't exist, economic powers of the world are forced to transport actual money from place to place. Adventure hooks galore.
If some adjacent kingdom uses a different standard of exchange, eventually a standard rate of exchange will develop; say, an eight-pin chip is equivalent to seven pop tabs. The exact number depends on the relative supply of tabs, chips, and whatever other commodities are traded across the border, and may even vary from one week to the next, but everyone involved stands to benefit from a standard, so everyone involved will do what they can to make sure that the standard terms are widely adopted, especially when that means exploiting every deviation from the standard rates for personal profit.
Jaid, I think your misunderstanding what crwydryny is proposing. He is proposing a viable representative currency using clean water as the base commodity.
It would be viable because the tokens are otherwise worthless, small, light weight, long lasting and difficult to devalue; while the base commodity is valuable, bulky, heavy and naturally deteriorates (through both use and storage).
The water purification plant/pumping station acts as a self renewing bank.
yeah that pretty much sums it up what I was getting at.
If I were going to have a commonly traded form of currency at this point it would most likely be, ammunition. As my campaign progresses, I will begin developing different forms of currency for the different areas.
I am a fan of gold and silver coins, and it has not been so long back that gold & silver coins were a staple currency in this country. One of my hobbies is collecting coins.
That being said, any metals that might have use could be used as a currency, that might be backed by anything from the purified water in a Baron's water tank on the hill, to the grain reserves in the silo, or even by pre-apocalypse valueables. Basically, there are a great many things that could be the basis or the backing of a currency for a particular Barony/kingdom/republic and so on.
I agree that the currency must be in a form that is easily transported, and not be something that is a consumable item. Nothing against pop caps, but I will not be using it as a form of currency in any campaign that I am GM'ing. In my opinion, it would be prehaps a 100 or more years after a apocalypse event before any real substantial currency would emerge, perhaps even longer. The Barter system would be the dominant system for a very long time. For example, how many thousands of years did Mankind barter before any currency arose??
In a apocalyptic society which has developed a way of currency, what would you make the currency be? Base it off of DnD's gold silver and copper piece system; heres one of mine
One old quarter = 10 tokens, or 100 aluminum can tops
One token = 10 aluminum can tops
I could see tokens and aluminum can top being switched though
If you played the game Metro 2033 using bullets as currency is a novel idea, because bullets unlike money we use today has avalue all on it's own. Todays money needs a backing of a market or government to have any ture value, that however is a moot point in a world where markets and governments (the one we are used to) no longer exist. The reason I say bullets is because if you have a copy of the D20 apocalypse book the price of ammo per bullet is very balanced. Also bullets are an interesting varient to use instead of actual cash.