Gold

Gold is the currency used in Diablo 3. All items bought or sold are paid for in gold, and as in Diablo 2, gold is automatically stored in a character's purse, without taking up inventory space. Higher level characters can carry more gold and store more in the town stash, though exact figures are not yet known.

As a convenience in Diablo 3, characters automatically pick up any gold they walk over, saving players valuable clicking time.

Gold in Diablo III

As in the previous games in the series, gold is the only currency in Diablo 3. Unlike many other RPGs, there is no value gradation of precious metals, ala copper, silver, platinum, etc.

Gold is obtained in exchange for selling items to NPC merchants, as well as found while adventuring. Slain monsters often drop gold, and it can also be found lying in the corners of levels, as well as inside objects of all types, such as chests, barrels, crates, and more. A new addition in Diablo 3 is the gold sometimes directly rewarded for completing quests.

The Economy

The Diablo 3 team has repeatedly stressed [1] their interest in having gold remain a viable game resource. It did not in Diablo 1 and 2, since high level characters perpetually had much more gold than they could spend. In game design terms, those titles needed more "gold sinks" to give players something worth spending gold on. Gambling was a perpetual use for gold in Diablo 2, but odds of obtaining a useful item via gambling were too low to motivate most players to keep gambling, once they reached the end game.

While the D3 Team has been vague about what gold may be used for, they have given a few hints. It's known that respecs and item modifications (unsocketing) will be expensive, and there will surely be other desirable ways to spend gold.

Jay Wilson described the creation of the game's economy, and named some of the ways the team is looking to make gold more valuable, in an interview from BlizzCon 2009. [2]

So, player economy and itemization are two of the last things you do. Mostly because nothing waits for them, but they wait for everything. Until you have vendors in working the way you want, until you have a lot of progression through your game, all your support systems and different items that you find - until you have all of those things - there’s really not a lot of point to doing any in-depth economy or item math. Most of the items that we’ve done so far are so there are actually items in the game. So, that being said, the key to doing a good economy is pulling out money at roughly the same rate that you’re putting it in. I say roughly because a little bit of inflation is okay, but deflation is generally bad.

As long as you’ve got a way to get it under control, you know, with DLC or an expansion, make an adjustment. So, having a lot of things for people to spend gold on is really important. Every system that we design, we go, “Oh, how can we spend gold here?” People have asked about a respec system, for example. We will have one. We haven’t designed it yet, but I guarantee you that you’ll have to spend a lot of gold. I can guarantee that because that’s one of the places we’d look at to try and balance the economy. There are a whole bunch of systems like that that we haven’t announced or are in progress. “Will you be able to remove gems from items?” Yes, you will able to and I guarantee you it will cost a lot of gold. Those are part of the ways that you handle and make gold valuable.

Inventory

Gold drops from monsters are deposited into your inventory by simply walking over or near the gold pile. To drop a specific number of coins, right-click on gold in your character's inventory. Type in the amount of gold that you wish your character to drop, and press the Enter key.

Background

During the long reign of peace that existed in Khanduras most towns and cities agreed upon a standard gold coin to use in trade. The Church of Zakarum has tried to have its own currency accepted as the new standard, but so far it has gained little acceptance. Although it would seem that the minions of the Three would have no use for gold coins, many demons hoard all the wealth that they can find.

Gold Value Speculation

It's unlikely that these are solid pieces of gold, and most likely gold plated pieces of other metals. A farmer would not otherwise afford actual pieces of gold. Another option would be that the mineral gold is significantly more common on Sanctuary than most traditional fantasy settings or our own world.