You might be curious: if you use the treasure tables in the 5e DMG, how rich will the characters be? This becomes important if you want to do things like give characters XP for GP found.
Here’s the breakdown: for each tier (a band of 4-6 levels) I’ve written a script which presents the average monetary treasure and provides a sample roll on the treasure table. (I’m using ~ as shorthand for “on average” here.)
What we see here is that, for each tier, average hoard value is multiplied by 10. At first glance, this seems like a problem. This is not granular at all, and treasure values don’t change for 6 levels at a time?? A closer look reveals that it might work quite well. The treasure quantity is tied to the monster’s level, not the PC’s level. If PCs take on monsters of varying but surmountable difficulties, they will naturally fight steadily increasing numbers of higher-tier monsters as they level up. For instance, if you imagine a group who fights monsters of their level +1d6-2, these big steps turn naturally into a nice curve. Not only it is a smooth average, it’s one with extremely varied rewards. That means that there’s lots of the “wow! I’m rich!” moments that make slot machines so popular.
Knowing how much money characters are “expected” to earn helps us gauge a lot of things about the economy. For me, the most important questions are a) when can characters afford domains? and b) can I give out 1 XP per 1 GP and ignore monster XP?
When will the players be afford to buy castles? Because of 1e tradition, I want people to be able to afford domains at around level 10, so I might price them at a few tens of thousands of GP. At that price, a tenth-level party, which will probably have picked up a few third-tier hoards, will be able to start affording them.
What about 1 GP = 1 XP? There’s no rules for that in the DMG, and you want to have some way to match GP to XP to figure out how long it will take to level. At straight GP to XP, are we looking at a full campaign taking, like, a few weeks or a few decades?
Well, according to the “standard” expectations of treasure hordes found per career, a 20th-level party will have discovered about 3 million GP, at a rate of about 3 treasure hordes per character level. It takes 255,000 XP to get to level 20, so that hoard is enough for about 8 characters to get to level 20. That means that, at level 20, GP=XP is in the right ballpark, but a little high.
How does 1 GP=1 XP fare at lower levels? It takes 300 XP to get to level 2, which means that the party has to find 1 tier-1 treasure hoard per character. That will take a while, considering that level 1 is supposed to be a training level. Tier-one treasures will generally net about 100 XP for each character in a four-person party, which makes advancement pretty slow. Tier-two treasures (monster level 5+) provide 1000 XP each, and become necessary for advancement at around character level 3. Tier-three treasures (monster level 11+) provide 10k XP each, and characters of level 6+ really need one or more tier-three treasure in order to advance in level. High-level characters need four or five such finds, which means that high levels take a lot more time to accrue. No one needs a tier-4 treasure (level 17+): its 100k XP would take a party of 17th-level characters to level 20 in one shot (assuming you could gain more than 1 level per treasure).
In short, the treasure expectations almost-but-not-quite work for 1XP=1GP. For that trick, the treasure finds really do need to be a little more regular. Here’s the fix I propose:
Whenever a monster is in the top half of a tier (levels 3-4, 8-10, 14-16) double the monetary treasure. This eases the speed bumps that slow down character advancement at certain points.
Ignore tier-four treasures. A steady diet of doubled tier-three treasures will allow high-level characters to advance after every two hoards (or once after a dragon hoard). A tier-four treasure of 300,000 GP might be fun but it is not necessary for character advancement.