Weights, measures and antique currencies adapted to roleplaying games

Copyright Julien Buseyne © 2008

Edited by Nicholas HM Caldwell for The Guild Companion

"The value of a currency represents the power and economic health of the government that mints it"

Translated from French into English by Sophie and Julien Buseyne.

This article will introduce the weights, the measures and the monetary system in use in most parts of Europe and of the Mediterranean basin during the period following the fall of the Roman Empire. The goal is to give players game features rather than simply serve up detail for the sake of detail. Considering this, the weights and measures system is mainly an atmosphere feature whereas the currency, and therefore the epoch economy, opens much more development opportunities. That's why the article has been split in two parts. One dedicated to weights and measures, the other to currency and economy. All through the article, we will constantly contrast the richness and depth of the game setting (and the opportunities it offers) to the fluidity of the system (and the ease it can be used within the game). More than ever, it's the game master duty to find the right balance. All of this is no more than a tool kit, the game master may choose to use it or not. We would really like to work on this subject thoroughly and propose a complete system displaying several levels of complexity in order to make it useful for all game masters. This would give matter for a full book and we don't have the opportunity for it at the moment.

Weights and measures


During the 6th century of this era, the weights and measures of the Roman Empire are in use in all Europe and in the Mediterranean basin. We will detail here the values of units of measurement in a way that may seem excessive. Most of the time, we recommend the use of the simplified measures. We are nevertheless giving all the information we could find, trying to be exhaustive and believing that game masters may choose to give their players the opportunity to have lands or engage in commerce. Note that using the units of measurement is not mandatory to play in an early middle ages setting (and it is unlikely that Justinian the First would rise from his grave to punish you if you don't). The choice is yours : simplicity or immersion. In the first case, go straight away to the currencies part and use whatever measures you may need. In the second case, your players are likely to find it a bit difficult at the beginning, but with time and practice, they'll become familiar to the use of pes, modius and libra. This will improve the ambience around the table. If they begin to count on their fingers on a duodecimal basis, then maybe things went a bit too far for them. The human brain is such a weak thing.

This article can also be used as a good basis for the learning of ancient weights and measures systems ; the sources used for it are very reliable. Game masters willing to use exotic weights and measures systems in their own original worlds may also inspire themselves from it.

Please note that this weights and measures system is really down-to-earth : base units being related to concrete realities for the people of this epoch.


Counting in Rome.

During antiquity, two numeration systems were used simultaneously: the duodecimal basis and the decimal basis ; this could be related to the Babylonian influence. The written numeration system in use during middle ages, before the arrival of Arabic numerals, is the Roman numeration which can be found easily on the Internet. This system uses the decimal basis. This epoch paradox resides in the use of the duodecimal basis (24 hours in a day, 12 months in a year) for weights and measures (and also for the monetary system). This can be explained in several ways. First of all, a human being has 10 fingers. He may count on them in decimal basis but has to find a subtle method to go farther than 10. But we all have (or rather those who don't lack body pieces) 12 phalanx on each hand (ignoring the thumb) which allows us to count easily up to 144 (one hand for the unities, the other one for the dozens), or 12². The duodecimal basis is thus more convenient than the decimal basis when faced with counting with the means of one's disposal. Moreover, 12 may be easily divided by 2,3, 4 and 6 whereas 10 can only be divided by 2 and 5. And finally, this epoch's maths are still deeply tainted by the inheritance of the Babylonian culture. They counted in a 60 basis,which is a multiple of 12. The Roman army was also originally divided into units of 60 men. Indeed, the two systems were strongly mixed.

Important values in duodecimal basis

The important values in duodecimal basis are the divisors of 12 and the multiples of 12. The only values frequently used are those of the 12 and 144 columns. The others are less common. We only give them to help recognize the values appearing frequently in the tables below.

/ 12
6 2
4 3
3 4
2 6
* 12 144 1728
2 24 288 3456
3 36 432 5184
4 48 576 6912
5 60 720 8640
6 72 864 10368
8 96 1152 13824
10 120 1440 17280
12 144 1728 20736

As you will notice, some values are commonly used in units conversions.

Weights and measures — full system


The reference unit for mass is the mina. A mina represents 1/60 of the mass of an amphora of water (the content, not the amphora FILLED with water), that is to say around 432g. The mass of an amphora of pure water corresponds to a talent. The other reference unit is hurled barley seed. The seeds chosen to evaluate the mass were the big ones in the middle of the barley ear. These seeds have indeed an equivalent average mass, as long as the ear is mature, whatever the epoch or the climatic conditions. The hurled barley seed will be abbreviated in HBS throughout the article.

1 talent = 60 minae = 80 librae = 25989.120g
1 mina = 16 unciae = 64 sicilici = 128 drachmae = 384 scrupuli = 768 oboli = 2304 siliquae = 6912 chalci = 9216 HBS = 433.152 g
1libra = 12 unciae = 48 sicilici = 96 drachmae = 288 scrupuli = 576 oboli = 1728 siliquae = 5184 chalci = 6912 HBS = 324.864 g
1 uncia = 4 sicilici = 8 drachmae = 24 scrupuli = 48 oboli = 144 siliquae = 432 chalci = 576 HBS = 27.072 g
1 sicilicus = 2 drachmae = 6 scrupuli = 12 oboli = 36 siliquae = 108 chalci = 144 HBS = 6.768 g
1 drachma = 3 scrupuli = 6 oboli = 18 siliquae = 54 chalci = 72 HBS = 3.384 g
1 scrupulum = 2 oboli = 6 siliquae = 18 chalci = 24 HBS = 1.128 g
1 oboli = 3 siliquae = 9 chalci = 12 HBS = 0.564 g
1 siliqua = 3 chalci = 4 HBS = 0.188 g
1 HBS = around 0.047 g

Solid volume (seeds for example)

The quadrantal is to the volume of one cubic pes. There are 48 sextarii in a quadrantal.

1 quadrantal = 3 modii = 6 semodii = 48 sextarii = 96 heminae = 192 quartarii = 284 acetabuli = around 26 litres
1 modius = 2 semodii = 16 sextarii = 32 heminae = 64 quartarii = 128 acetabuli = 8⅔ litres
1 semodius = 8 sextarii = 16 heminae = 32 quartarii = 64 acetabuli = 4⅓ litres
1 sextarius = 2 heminae = 4 quartarii = 8 acetabuli = 54 cl
1 hemina = 2 quartarii = 4 acetabuli = 27 cl
1 quartarius = 2 acetabuli = 13½ cl
1 acetabuli = 6¾ cl

Liquid volume

An amphora contains a cubic pes, like the quadrantal for solid materials. Both quadrantal and amphora are worth 48 sextarii. The sextarius may thus be considered as a reference unit for volumes. Its volume, much alike a half-litre will be convenient for players. Hemina, trians and sextans are half, third, and sixth of a sextarius. These were common subdivision units but they are not really worth using, all the more since trians may be mistaken with triens, the third of a solidus.

1 culleus = 20 amphorae = 40 urnae = 160 congii = 960 sextarii = 1440 cheonix = 1920 heminae = 2880 triens = 5760 sextans = 11520 cyathi = 46080 ligulae = 520 l
1 amphora = 2 urnae = 8 congii = 48 sextarii = 72 cheonix = 96 heminae = 144 triens = 288 sextans = 576 cyathi = 2304 ligulae = 26 l
1 urna = 4 congii = 24 sextarii = 36 cheonix = 48 heminae = 72 triens = 144 sextans = 288 cyathi = 1152 ligulae = 13 l
1 congius = 6 sextarii = 9 cheonix = 12 heminae = 18 triens = 36 sextans = 72 cyathi = 288 ligulae = 3¼ l
1 sextarius = 3/2 cheonix = 2 heminae = 3 triens = 6 sextans = 12 cyathi = 48 ligulae = 54 cl
1 cheonix = 4/3 heminae = 2 triens = 4 sextans = 8 cyathi = 32 ligulae = 36 cl
1 hemina = 3/2 triens = 3 sextans = 6 cyathi = 24 ligulae = 27 cl
1 triens = 2 sextans = 4 cyathi = 16 ligulae = 18 cl
1 sextans = 2 cyathi = 8 ligulae = 9 cl
1 cyathus = 4 ligulae = 4½cl
1 ligula = 1 cl and 1/8


Surfaces measuring is not essential for roleplaying games. We nevertheless give these units for game masters who may be willing to let their players buy an estate. The actus quadratus is a square actus. It's the base unit for surfaces.

1 saltus = 4 centuriae = 201.6 ha
1 centuria = 100 heridii = 50.4 ha
1 heridium = 2 jugeri = 5040 m²
1 jugerum = 2 actus quadrati = 2520 m²
1 actus quadratus = 4 climae = 30 acti minimi = 144 scripuli = 1260 m²
1 scripulum = 100 pedes quadrati = 8.75 m²
1 pes quadratus = 875 cm²


Distances measuring will be mainly useful to calculate walking distances but also the length of products such as fabric or wood. This system allows numerous scales of sizes.

1 leuga = 1500 passi = 7500 pedes = 2.223 km
1 milliarium = 1000 passi = 5000 pedes = 1.482 km
1 stadium = 125 passi = 625 pedes = 185.25 m
1 actus = 24 passi = 120 pedes = 35.568 m
1 pertica = 2 passi = 10 pedes = 2.964 m
1 passus = 2 gradi = 5 pedes = 1.482 m
1 gradus = 2,5 pedes = 0.741 m
1 cubitus = 1,5 pes = 44.46 cm
1 pes = 4 palmi = 29.64 cm
1 palmus = 4 digiti = 7.41 cm
1 digitus = 18.525 mm

Simplified system


Proposed system : keep talent, mina, libra, uncia, scrupulum, siliqua and seed.

1 talent = 60 minae = 25989.12 g
1 mina = 4/3 libra = 433.152 g
1 libra = 12 unciae = 324.864 g
1 uncia = 24 scrupuli = 27.072 g
1 scrupulum = 6 siliquae = 1.128 g
1 siliqua = 4 HBS = 0.189 g
1 HBS = 0.047 g

Solid volume (seeds for example)

Proposed system : keep quadrantal, modius, sextarius, acetabulum.

1 quadrantal = 3 modi = 26 l
1 modius = 16 sextarii = 8 l and 2/3
1 sextarius = 8 acetabuli = 54 cl
1 acetabulum = 6¾ cl

Liquid volume

Proposed system : keep culleus, amphora, sextarius, cyathus, ligula

1 culleus = 20 amphorae = 520 l
1 amphora = 48 sextarii = 26 l
1 sextarius = 12 cyathi = 54 cl
1 cyathus = 4 ligulae = 4½ cl
1 ligula = 1 cl and 1/8


Proposed system : keep the following units. The pertica is kept to be coherent with surface measure units but it may be ignored if the game master prefers to simplify the measures.

1 leuga = 1500 passi = 7500 pedes = 2.223 km
1 milliarium = 1000 passi = 5000 pedes = 1.482 km
1 actus = 24 passi = 120 pedes = 35.568 m
1 pertica = 2 passi = 10 pedes = 2.964 m
1 passus = 2 gradi = 5 pedes = 1.482 m
1 pes = 4 palmi = 29.64 cm
1 palmus = 4 digiti = 7.41 cm
1 digitus = 18.525 mm

Currency and trade


Currency represents the " ready-to-use" part of an individual or a group's wealth. Its purpose is also to act as a solid basis from which the value of trading goods is evaluated and as a easily transportable exchange token. Without currency, goods for exchange must be carried from their place of storage to the place of exchange (which may lead to damage or loss of a part or all of the goods). Then, once there, their owner may not find anyone willing to exchange the goods he desires to acquire for the goods he has brought for barter. Wealth reserve, ease of transportation, universal exchange tool: here are money's advantage. On the downside, it requires a centralized state to mint money and guarantee its value and a code of laws to regulate its use. An advanced government system is thus necessary for mints and laws to exist and a high degree of peace to uphold them.

One must also realize that even nowadays, the best part of one's wealth is actually made of real estate, livestock, movable property and harvests rather than money. As a consequence, the currency (be it metal, paper or virtual) one possesses is an indication of its readily usable financial power and social status. At a given moment, money supply is a constant value; the more money one's possesses, the more power it wields when compared to other individuals. This logic was applied in a down-to-earth way during the antiquity: rich people bought official positions from the state and were expected to spend their money for the development of cities. Last, but not least, the value of a currency represents the power and economic health of the government that mints it. Just take a moment to think about this: Byzantium minted solidi (later on called nomismata) for six centuries at the same value. When compared to todays unstable markets, it leaves one wondering how an autocratic state such as Byzantium actually performed this feat.

As a game master, you may use currency only as a means of exchange or use it like we suggest in this article. Consider what follows as a set of tools: you may use them or leave them in the toolbox. The choice is yours. Nothing here requires inclusion for the setting to be complete.


A quick look at coins minted after the fall of the Roman empire

During the 6th century, between 570 and 615 AD, the money based on the gold standard enjoyed a period of great stability. Consider the following as a reference for the entire century.

The gold libra is divided in 72 golden solidi, each one worth 24 siliquae of pure gold. Siliquae were actually minted in silver, for golden siliquae would have been far too light and small to be used. There are 1728 silver siliquae in a gold libra. The siliqua itself is worth 12 bronze folles, which weight and value were highly unstable through time. The bronze follis is divided into 40 bronze nummiae. The actual number of folles that were worth a siliqua was (and still is) subject to much debate. We chose the values given here and considered them stable to give game masters something they may use easily. The gold libra is the standard for money and the value of the silver libra is estimated in gold. Actually, few people own gold librae. Gold is stored in this form only by the state or powerful individuals after collecting taxes or harvesting the spoils of war. It is kept in this form for mass trading, funds transportation or until it is used to mint new coins. Player characters may get their hands on gold or more likely silver librae but they may find difficult to exchange them for coins or goods without catching the eye of authorities; people talk. Usually, a gold libra is stamped to guarantee its mass and purity, a practice still in use nowadays.

The gold solidus is the gold coin used for large scale or livestock trading and diplomacy. It is possible for common folk to have one but it is nonetheless a symbol of wealth. The semissis is a rare coin worth half a solidus and the triens is a common coin worth a third of a solidus. Tributes, taxes, weapons prices and public utilities costs were calculated in solidi (but could be paid with goods or with smaller coins).

The siliqua stand for a weight of 0.189 g of pure gold (just like the unit of weight measurement). For practical issues, it was minted in silver and weighed around 2.6 g. There was a half-siliqua, a third-siliqua and a quarter-siliqua weighing respectively around 1.3 g, 0.87 g and 0.65 g. It was a rare coin minted to celebrate important events. Some people would propose more than their actual value for some of them.

The follis is the large bronze coin. Most daily exchanges and wages were paid in folles. Its value varied a lot through time but consider it to be stable throughout the century. We nonetheless give below some information for those game masters that would like to use economic data in their games.

All of these coins were used as currency in the Byzantine world and beyond. In the Byzantine sphere of influence, a lot of coinage was available and direct barter for goods was limited. However, at the end of the sixth century clouds gather above the Byzantium economy: ruinous and inefficient bribes sent to the Frankish kings, tributes paid to the Avars, and the back draft of the very costly reconquests of North Africa and Italy empty the Byzantine treasure reserves and money supplies drop, giving some more room to barter and other kinds of exchanges for which money is not necessary. However the values of gold and silver remain roughly the same until the eleventh century. Visigoths experience a very similar situation. Frank and Saxon folks don't have a lot of coins to trade with. The most numerous type of coin in Gaul is the triens, the third of a solidus. Bronze coins exist but they are not present in numbers great enough to be desired by merchants or farmers. As a consequence, barter is widespread until the 8th century and Carloman's reforms, which bring back the use of numerous silver and bronze coins for exchanges. Nomadic tribes use barter among themselves. Chiefs hoard gold and silver for prestige and for later use with neighbours (buying alliances for example); stocks could weigh several tons. Bronze coins are melted and used for making belt buckles and other ornaments.

Money in game

During the longest period of stability for bronze in the 6th century, from 570 to 615 A.D., nearly all of Europe use this coinage system:

Gold Standard
Coin Metal Mass in g Is Worth
Libra gold 328.6 72 solidi
Solidus gold 4.55 24 siliquae
Siliqua silver 2.6 12 follis
Follis bronze 11 40 nummiae

There were coins representing divisions or multiples of other ones. We provide them for those hungry for details but don't recommend to use them in game.

1 gold libra = 72 solidi = 144 semoss (semissis) = 216 triens (tremissis) = 1728 siliquae
2 siliquae = 1 hexagram
1 follis = 2 half-folles
1 decanummia = 10 nummiae
1 pentanummia = 5 nummiae

Gold/silver change rate remains the same from the 5th to the 11th century. As for bronze, you may also decide it does not change too. If you want to walk the hard path, make it vary according to the rates given later in the article. Another way to simulate variation is to decide the number of folles per siliqua is the same but their weight varies according to the change rate. A last way to do it is to decide that you need a change in the change rate (to embarrass players that are acquiring too much wealth over a short period of time, for example) and that's about it. A quick decree from the emperor does the trick. Whatever you decide don't forget that roleplaying games are about having fun. If your players are not into trading or a world's economics, just don't burden the game with things that will confuse them. Keep the game smooth, then think about immersion and details.

Here is a quick overview of fixed change rates for gold, silver and bronze:

Change Rates
Change Gold Silver
Silver 13.71
Bronze 715.03 52.15

Remember, coins are struck at a given number per metal libra:

  • 1 gold libra yields 72 solidi.
  • 1 bronze libra yields 29 folles.

The breakdown of each coin (or ingot) into the directly lesser one is as shown below; it is read this way: a libra is worth 72 Solidi

Coinage Breakdown
Worth Libra Solidus Siliqua Follis
Solidus 72
Siliqua 1728 24
Follis 20736 288 12
Nummia 829440 11520 480 40

Calibrating the system to your needs

Game masters willing to give an "early medieval mood" to their games without losing their players along the road may use a very basic version of the epoch's coinage. The principle is to use a "currency unit" that represents wealth in game and acts as a bridge with the Rolemaster (or other game) system at the same time. This way, it is possible to use the charts from "… and a 10-foot pole" and quickly import values from another campaign.

The "currency unit"

The "currency unit" is the smallest currency in the setting. Here, it is worth one nummia. The game master may decide to manage trade and wealth in nummiae only, assuming everybody actually carry solidi, siliquae and folles too. Of course, this also assumes you ignore local differences like in Gaul, where the smallest coin is worth thousands of nummiae. Just consider everybody is using the same money everywhere and you'll be just fine. Just use the word "nummia" and you'll create a bit of immersion.

In the Rolemaster system, the "currency unit" is worth one tin coin. Iron coins are overlooked, convert them into one tin coin or just ignore them.

Converting values in Rolemaster into early medieval currency

In the Rolemaster system, all the prices are noted in decimal count. One expects the conversion from this simple system into a partly duodecimal, partly decimal one to be hellish. It actually is a mind bender. Let's go medieval:

1 nummia = 1 tin coin 1 follis = 4 copper coins
1 siliqua = 4 bronze coins and 8 copper coins
1 solidus = 1 gold coin, 1 silver coin, 5 bronze coins and 2 copper coins
1 gold libra = 82 gold coins, 9 silver coins, 4 bronze coins and 4 copper coins

Nothing a simple open office calc sheet can't solve anyway, click here to download it

Since this is behind us, let's focus on a more serious matter. A comparison between the charts for middle ages in "... and a 10-foot pole" (10FP from now on) and scholar data yields interesting results. For example, a simple worker daily wages in 10FP are worth 2 bronze coins, or 5 folles. Just the daily wages for a Byzantine worker. These wages are said to be the price for a modius of wheat. In 10FP, a bushel (35 l, almost exactly 4 modii) of wheat is worth 4 to 8 bronze coins which gives 1 to 2 bronze coins for a modius. Once again, the prices are the same. Another example: a Byzantine warhorse maximum value was 10 solidi. In10FP, such a horse is worth 20 gold coins, or 17 solidi, which is a bit high but is nonetheless in the same range. Other prices were compared and all in all they are correct or in the good range. 10FP may be used with a 6th century setting without much work.

It is possible to build a chart with historically accurate prices but the amount of work required to do so would be completely out of proportion with the gain of quality for the game since 10FP already fits the job. However, some indications can't hurt:

Daily wages: 284 nummiae or 7 folles and 4 nummiae. Annual wages: around 9 solidi.
Foot soldier
Daily wages: 158 nummiae or 3 folles and 38 nummiae. Annual wages: around 5 solidi.
Daily wages: 200 nummiae or 5 folles. Mean yearly wages (dependent on work time, usually 4 months): 2 solidi, 2 siliquae et 10 folles.
Master craftsman
Max daily wages: 1400 nummiae or 35 folles. Mean yearly wages (dependent on work time, usually 4 months): 14 solidi, 19 siliquae and 10 folles.
A modius of wheat
200 to 440 nummiae or 5 to 11 folles.
Daily ration per person
40 to 80 nummiae or 1 to 2 folles.

Variable change rates

It is possible for a game master to use economics as a tool for his game. Variable change rates are a way to do this. As stated above, gold and silver show a remarkable stability through the centuries. Bronze, however, is subject to important variations all through the 6th century A.D. And food and goods prices trebled in the same period. Other variations occur during famine (food prices rocket to ten times their usual value) or war (access to some raw materials may be impossible). Also, local markets may crumble or explode whereas the global market is not experiencing any kind of important variation. Don't forget that prices are low in production areas and high in consumption areas, and crafted goods always sell for more than raw materials. A game master whose players want to trade should prepare charts for goods prices in various places, and plan some variations. Arguments during the weighing of money, attempts at fraud or theft while bartering, discussions when trying to buy low and sell high are good adventure starters and bring life to the game. One expects players to run after a merchant that just conned them into paying twice the usual price for some goods.

Bronze change rate variations are not easy to handle for players and, at any rate, should not be too frequent. A dedicated game master may use this parameter in order to simulate a living economy in his game. However this option should be disregarded if your players are not interested in this degree of detail; you don't want to invest time and work into something that will turn out to bore them.

Bronze Change Rate and Folles per Solidus
Year Folles/libra Mean weight Folles/solidus Nummiae/solidus Bronze/gold
498 36 8.5 420 16800 840
512 18 17.5 210 8400 840
539 14.5 22 180 7200 893.7931034
542 16 20 180 7200 810
548 18 18 180 7200 720
551 19 17 180 7200 682.1052632
565 21.5 15 240 9600 803.7209302
570 25 13 288 11520 829.44
578 29 11 288 11520 715.0344828
615 36 3 352 14080 704
624 54 6 532 21280 709.3333333
629 32 10 288 11520 648
631 56 5.5 576 23040 740.5714286
639 72 4.5 704 28160 704

Gold and bronze currencies supply

During the sixth century A.D. Byzantium tax income for Levant and Greece amounts to five million solidi. If a tax rate of between 10% and 20% was in use, this suggests that 25 to 50 millions solidi circulated in this part of the Empire. Add Byzantine gold reserves (as high as 25 millions solidi in periods of wealth) and we can guess that tens of millions solidi were circulating. Money being less frequent in the rest of Europe, we may assume there was a bit less than 100 millions solidi available in Europe and the Mediterranean basin.

Considering 40 millions people inhabited this part of the world at that time, each inhabitant possessed around 2 solidi in coins at a given moment. Of course, wealth differences between territories and social classes prevent this mean wealth from being a reality. Many only possessed bronze coins and a few hoarded hundreds of solidi. Most money flowed in bronze currency but it is very hard to estimate its supply. Just assume it is far greater than gold currency supply and that it is mainly in the hands of the small folk. As a consequence, a character owning several dozens of solidi is rich (and may well be the focus of unwanted attention). It is up to the game master to decide if he desires to take this wealth ladder into account. If he does, he must remember that a Frank, a Lombard or a Saxon may posses a few coins but also a farm and livestock, weapons, furniture... in such quantities that he will be considered a rich man. Two ways lie ahead: keeping a kind of logic in the economics of the setting and using them as a lever to provide depth and realism to the players or just consider money and wealth as a means of exchange for players.

Frauds and currency

Dishonest PCs or NPCs may alter coins in different ways in order to increase their wealth or buy goods at a lower cost. Here are some ideas how to do this.

  • Scratch away a bit of several coins in order to gather precious metal and melt it into ingots or new coins. Then, the scratched coins are used to pay for goods and services. The more scratched a coin is, the more likely someone may notice the fraud. For example, a coin that was scratched in such a way that fifty coins yield a new one may be noticed on a successful awareness roll (hard). Weighing scratched coins reveals the fraud automatically.
  • A daring trick is to cut coins in two through their rim, so that a coin yields two half coins that look perfect on one side. Such coins are then used to buy goods from a dupe (or reimburse a debt). It requires wits, a quick tongue and even quicker hands to have the dupe accept the coins without noticing the fraud (successful trickery or acting static maneuver roll -- difficulty to GM's discretion). The culprit should be well advised to run quickly after passing the next street's corner anyway. The dupe won't be fooled for long. Of course, weighing a coin bag containing cut coins will reveal the fraud instantly.
  • Coins are theoretically made of pure gold or silver, or of bronze alloy. Precious coins are actually often alloys containing a high degree of precious metals (often a 0.995 to 1 ratio) and a small part of tin or brass. An ambitious and well equipped con artist may melt precious coins and add a larger part of tin or brass to the alloy and mint false coins. For example, melting 24 pure gold solidi and minting new ones containing only 22 siliquae of gold (instead of 24) yield two more solidi. This operation requires furnaces, moulds and metallurgy, metal engraving and minting tools; and the relevant skills, of course. To carry out the operation successfully the counterfeiter (or the group of counterfeiters) must successfully roll for the following static maneuvers: metallurgy (to melt the coins, modify the alloys, pour them and let them cool properly -- difficult), metal sculpting (to engrave the dies -- difficulty depends upon the original coin design) and operating equipment (to properly mint the coins -- medium). If the operation is successful, the fraud is extremely hard to notice by sight or by touch, very hard by weighing the coins and hard by comparing the mass per weight ratio of real coins and false coins.
  • Paying large sums with gold plated lead ingots is an old trick. It is extremely hard to notice the fraud by sight or hand, but simply scratching or weighing the ingots will reveal the fraud instantly.
  • Bronze was never used for settling large trade agreements. Some gold or silver coins were hacked to pieces in order to pay the precise amount of money required. The coins and bits were then weighed until the agreed sum was paid. An easy trick was to weigh down the weights in order to make others pay more or to lighten them in order to pay less. This kind of fraud is actively chased down by authorities and judges sentence culprits to hefty fines. On top of that, the victims of such frauds were more than willing to pay back the scoundrel in blood money. Arguments about the weighing of gold and silver were numerous and are a good way to liven up a game session.

You, or your players, will find many other ways to dupe PCs or NPCs. On a side note, governments and official mints were the first to cheat with gold purity in coins in order to solve treasury issues.

Do you need all of this?

Roleplaying games are about having fun. Few players will find it entertaining to convert currency from 10FP to Byzantine coinage. But they could like being traders. As a game master, you need to prepare the game to a small extent before running it. First, assess your players' motivations and evaluate what you need to make them feel like they live adventures in the sixth century. Don't even consider adding complex trading elements to your setting if your players are simply out for blood and loot. Second, assess your ability to run an economy. Don't overwhelm yourself with too much work. Keep it quick and easy. For example, if your players are used to visiting three cities, just prepare prices in these 3 cities and one or two more, just in case your players want to seize new opportunities for trading. Third, keep a lot of things secret from the players. Let them obtain the information through their own means. It is an easy and efficient way to bring life to the game. If the players want to trade linen fabric, let them find themselves all the information they need about trade routes, production sites and local market openings.


It is not expected that a game master will use all the material from this article. However some of the information may be of some interest to those looking for an original currency system, some basic knowledge about trading or ancient units of measure.

Beyond simple mood and setting tools, those elements may also be used for narrative purpose. PCs duped by counterfeiters may want to bring the scoundrels to justice or deal with it themselves in their own style. A famine always catch the eye of traders out for easy profit. PCs may set sail to a famished city in order to sell their stock of grain to the best price. Once there, they might notice some shady individuals dealing in some kind of strange activities...

Try to put the PCs motivations in an economic perspective: crime, greed for power, political schemes usually have the betterment of one's situation through the acquisition of wealth, helping one to insure his and his family's security and well-being. Make sure your players don't forget it.


On the web:


  • Description générale des monnaie byzantines par J. Sabatier. No ISBN. Available on google books.
  • Essai sur les système métriques et monétaires des anciens peuples depuis les premiers temps historiques jusqu'à la fin du khalifat d'orient par Don V. Vazquez Queipo. No ISBN. Available on google books
  • Traité de métrologie ancienne et moderne par M Saigey. No ISBN. Available on google books

For the remainder of the bibliography, please consult this webpage There is only a French version at the moment, sorry.