# Tag Info

126

Money sinks are I guess the only real answer. Which means items or currency getting lost forever. Eve Online blatantly has this through the mass destruction of items and ships through pvp (only partially replaced by insurance). Eve also has many other money sinks such as office rent, station fuels, ammunition etc. Other games have similar consumables, ...

86

You can use int, and consider everything in cents. \$1.20 is just 120 cents. At display, you put the decimal in where it belongs. Interest calculations would just be either truncated or rounded up. So newAmt = round( 120 cents * 1.04 ) = round( 124.8 ) = 125 cents This way you don't have messy decimals always sticking around. You could get rich by ...

62

Okay, I'll jump in. My advice: it's a game. Take it easy and use double. Here is my rationale: float does have a precision issue that appears when adding units to millions, so though it might be benign, I would avoid that type. double only starts getting problems around the quintillons (a billion billions). Since you are going to have interest rates, you ...

54

Notice that only one person here before me has given the correct answer - "currency can't inflate if there's a limited amount of it." Indeed, with infinite resource generation, currency will actually deflate, as the amount of resources goes up and the amount of currency stays fixed. It's an economy. You're not the Fed. Stop minting currency, and stop ...

47

Several of the above answers mention some important ways to reduce inflation but there's a few important money sinks that deserve some more explanation: Economic exchange fees: These are fees from converting a player's wealth from one form to another. A prime example of this in nearly every game is the vendor sell price. NPC vendors will always pay less ...

29

In my experience, the reason you don't see this very often (at least in the US) is "it's very complicated, we as game developers lack the expertise, and there isn't much profit in it." Online gambling laws are really complicated. I'm not even going to pretend my limited comprehension of legalese is up to the task of parsing them. It's not necessarily very ...

22

One crucial aspect that I don't see people mentioning here: make sure you have at least one money sink that scales up automatically as people get richer. Fees for walking around the world and armor repair won't scale up, since they're based on fixed values. Special novelty items that you can buy for large amounts of gold do scale up, in an economic sense, ...

22

Creating resources endlessly is an issue but completely closed systems have their downfalls too. Take a look at Shattered World. Completely closed economy with player run shops, banks, etc. Monsters in the world were actually equipped by items purchased from player shops by the game. The hoarding instinct mentioned above killed the game though. There were ...

21

Floating point types in Java (float, double) are not good representation for currencies because of one main reason - there is a machine error in rounding. Even if a simple calculation returns a whole number - like 12.0/2 (6.0), the floating point might wrongly round it (due tho the specific representation of these types in memory) as 6.0000000000001 or 5....

17

For small scale game and where process speed, memory is important issue (due to precision or work with math co-processor can make painfully slow), there double is enough. But for large scale games (for example, social games) and where process speed, memory is not limited, there BigDecimal is better. Because here, int or long for monetary calculations. ...

17

Some suggestions to bring more cards into the game: When a player wins a match, reward them with two cards: One from the losers deck and one newly created one. You might also consider giving a generated card to the loser to compensate for the loss, otherwise they would progress backwards, which is a real motivation breaker. Reward players for playing by ...

13

You want to store your currency in long and calculate your currency in double, at least as a backup. You want all transactions to take place as long. The reason you want to store your currency in long is that you don't want to lose any currency. Let's suppose you use a double, and you have no money. Someone gives you three dimes, and then takes them back. ...

12

Currency sinks alone won't save you, even if you're not creating free money from resources. If your number of players changes, then the distribution of money will change also. And if you scale the money supply linearly to match the number of players, that does nothing for the inequality of wealth distribution (which will tend to get worse as the numbers rise)...

11

I've been doing a lot of research on this topic in the past several months and have gathered quite a bit of resources that you might find useful. Although I haven't come across an actual book about it, these articles are pretty long (and comes in several parts) so they are pretty close :) Take a look at these to get you started: Virtual Economic Theory: ...

11

This basically boils down to basic economic theory, more specifically the concept of market transparency. When someone wants to buy or sell a fungible good (like most items in a common MMO game), they will look for the best available offer on the market and take it. In order to find this offer, they need to obtain full market transparency by looking at all ...

10

Nickson104 already wrote a pretty nice summary in his comment. I've been playing the game since early beta and I prefer the small AHs, so this might be a bit subjective, but overall the most important points have been mentioned already: A global AH makes it far easier for players to find the item they want at the cheapest price (which they usually want as ...

9

Add a money-sink that trades money for services such as temporary buffs, items, etc. The money disappears and afterwards (say a few minutes or a week), the service disappears. Possible services can be: extra experience special pet access to a dungeon speed buff (surprisingly useful in a MMO) temporary access to a spell

9

Money sinks are the obvious answer, as you say. You can do this through incentives ("pay 1M gold for this cool new sword") or through regular losses ("your weapons and armor degrade over time, pay gold at the blacksmith to restore them"). You can also try to find core mechanics that don't involve infinite-spawn -> farm -> net increase in global wealth. ...

9

The main thing players want from an economy is control. A player wants to feel like advanced knowledge of the economy will yield economic rewards. This does place some responsibility on the dev but a lot comes from the players. I'm gonna refer to World of Warcraft here because I have quite a lot of experience with the in-game economy there. Firstly, the ...

9

My question is why are there not more games which take this approach of a game economy tied directly to real money? I think the answer lies in what a game is. To most people, a game is something where you relax and can have carefree fun. Some people will have more fun if game money is real money, but others will have less fun. So inherently it seems ...

8

I think one issue here is that minerals and actual currency are separate things. Anyway, one way to combat inflation would be to limit currency generation - in a real economy currency is created at a fixed rate, not when people earn it. Essentially, when you kill an NPC and steal their wallet you would be taking from the "pool" of NPC money. As the NPC money ...

8

Multiple currencies works for a lot of Facebook games. Consider Mafia Wars - when dollars were too inflated, they added "Cuba" which required an entirely separate currency. Then later Bangkok, etc. Also it's fairly standard in Facebook games to have a separate currency that you can only acquire large amounts of by paying real money. This way, the basic ...

8

Not mentioned yet are services as money sinks. So the player uses some of the inflated money to buy a service (like health boosts and speed increases), which is essentially intangible and at the end of the service period, value disappears from the economy. This helps to counter the feeling that the player is buying something pointless (such as vanity items) ...

8

You do need money sinks, but you can also encourage people to keep the items they receive in circulation, instead of NPCing them. If the benefit of selling an item to an NPC is minimal in comparison to trading with another player, then the economy will be self-sustaining. Requiring players to pay a fee (whether monetary or farming related) before being ...

8

There are arguments to both options. Single Currency - usually simpler for players to understand Multiple Currencies - allows more flexibility to in future optimizations For a single player action game I don't think you need more than two. Three of four currencies is something that is usually reserved for resource management games where you actually gain ...

8

I'd go as far as to say that any value which may be displayed to the user should almost always be an integer. Money is only the most prominent example of this. Dealing 225 damage four times to a monster with 900 HP and finding that it still has 1 HP left will subtract from the experience just as much as finding that you are an invisible fraction of a penny ...

7

Don't prevent inflation. You can fairly easily measure how fast currency is changing hands. Track it, and have the game automatically adjust NPC prices and drops accordingly, with a slow moving average so that prices don't spike. Just use a Big Integer for quantity and you'll be fine.

7

You've got a few different options. My preferred option is to (even if its not), make it look like a real world (or as it appears in your case, real galaxy) economy. To do this, you want each region/store to have an initial price. Such an initial price should be broadly similar over every store, and then similar to the prices nearby. You could generate them ...

7

When you allow players to not just pay you money but also get out money, your game can easily fulfill the definitions of both banking and gambling which are both heavily regulated in many jurisdictions. While some game companies might feel comfortable with managing a gambling business, very few possess the know-how which is necessary for operating a bank in ...

6

It is possible to limit the speed at which new resources are added to the game. For example limit the number of gold a player can dig per day. A less obvious limit is to apply luck to random events. If a player has lots of karma it is likely that he gets drops, but the karma is used up and has to be renewed by doing quests.

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