I came across a GM asking the question of what to do about encumbrance for all those treasures the players find in the dungeons they loot. My knee-jerk reaction was "Nothing, nothing at all" but I feel it needs more explanation than that.
Who Cares about GP?
In OSE, Labyrinth Lord, S&W, clones, BECMI, 1E, and many 2e and earlier versions of Dungeons & Dragons, 1 gold = 1 XP. Those XP usually don't count until the players get that loot home and tucked away somehow. Some GMs don't even count it until you spend that gold on something related to your character or class.
Just bring the gold home
This seems like a pretty straight forward thing and many GMs don't want the accounting of encumbrance until they realize a player mentions that they are carrying 9,000 coins around in their pocket.
Some systems mark 10 or 20cn(coins) per pound, 5E Dungeons & Dragons assumes 50 = 1 lb. If we make a wide assumption that a fantasy coin weighs about the same as a quarter, that's about 80 per pound. 9,000 coins at that rate would be about 112 pounds! A thief sneaking around with 112 pounds of coins on them simply isn't sneaking anywhere. At this point encumbrance has to become part of the conversation at the game table.
I don't want to bog down my game with accounting
I get it. especially in Basic - clone games where rules are light. Counting every coin seems like a hassle. I personally run a loosey-goosey version of all this. I keep a casual eye on what players are toting around and don't sweat the encumbrance in more than general terms.
"You are wearing a lot of stuff with a full pack, you're generally "encumbered" and slowed by 3 movement."
I also note when a player opts to buy the famous 10-foot-pole. A ten-foot-long wooden pole is a GIANT hassle to tote around. No one carrying one should ever "forget" they have it. Running from gnolls through the woods? Not with a ten-foot-pole. I encourage anyone who doubts that statement to purchase or cut a 10-foot-long pole about the girth an adventurer would expect. Then take off running through as thick a wooded area as you can find. Try just walking through the door of your house with it, or around the corner of a hallway. The ten-foot-pole discussion may be best held for another post, this is about encumbrance.
You defeat the Boss Monster!
The boss defeat isn't the end of the adventure, it's simple the crescendo of action. When that boss monster has 90,000 copper, 22,000 silver, 10,000 gold, various tapestries, artworks, statues etc. the next adventure begins right there in the lair. This is where my fellow GM was struggling. they wanted to find a way to just let the players get the loot home to start the next quest. They were seeking a way to explain piles of gold just flowing into the coffers. I am thinking that THIS adventure isn't over yet. So why rush?
My response of what to do about it is "nothing at all". This is a puzzle the adventurers have to figure out if they want all that sweet juicy XP. It's still a fun part of the current quest. I have had players leave literally thousands of XP behind because they didn't carry out artworks that were masterly crafted items, tapestries, and statuary. A roll of "art" on the treasure table doesn't mean a nice little painting.
What Happens when the Boss is Gone?
So the heroes defeated the boss. In the dungeon they have found a master-carved fireplace mantle, an obsidian 4' tall sculpture, 2 large tapestries, and the afore mentioned coins. It's a veritable fortune! It's also worth some leveling up if they can get just 70% of it home. It weighs a ton and takes up a bunch of space. Encumbrance for something this size can be calculated or summed up. You could just go with it literally being a ton (2,000 pounds) as a general guess or maybe you want to take a minute and do a little math to be more accurate now that it's back in the adventure part of the game.
With items like this, it is time to pay at least a little attention to encumbrance. You can do this without it bogging down the game. Completely ignoring it and letting players just pop a ton of big bulky things in their packs may lead to a Monty Haul and you losing control of your game later when bigger treasure comes along.
If they all go back home as a unit with the intent to return later, it's likely the local kobolds, goblins, humans, any other opportunists will loot the place with as much as each can carry away. That means they are also carrying away party XP. If the local monster population find out the boss is gone, they'll likely immediately start snooping around for their share. Those players left to guard the treasure have a threat on their hands. Some monsters (or local NPCs) may coordinate hastily to take down the weakened heroes and claim the entire treasure before they can heal their wounds.
What often happens next is that the party will send out their swiftest and most charismatic player with plenty of gold to the nearest town to hire guards, oxen or horse-drawn cart(s), and/or laborers.
The player running to town, if you don't want to bog down play with bandits on the way, will have some roleplaying to do procuring the items and help. Do they tell the local workers that toil for 3 or 4 days for a single silver that they want them to come carry out tens of thousands of gold coins for them? How does this affect the local view of the characters?
"Yes farmer brown, I'd like to hire you and your team of horses for a couple of days. You mentioned that would be 10 silver? here you go.
Cargo? yes, we're going to be hauling back 90,000 GP worth of coins and rare treasures... we might get raided, thanks for the help."
Suddenly Farmer Brown might want to renegotiate the rate.
Once the aid is secured and rates agreed upon, local "monsters (including ambitious peasants and others)" know the boss is dead and see men hauling cart-loads of coin and treasure out of the lair. This is ripe for raiders and some good strategic bandit battles. A force of 10 or 12 orcs might be something to deal with, but a dozen kobolds following who don't want to fight there becomes new challenges. They'll be nabbing arm loads of coin off the cart one at a time and just fleeing while the PCs defend their loot.
OK, you get the treasure home!
Even after returning with such a treasure and claiming their hard-earned XP, the players may now find a fair amount of new "friends" they've never seen before hanging around. Prices at their inn may suddenly jump, the cost of goods might rise for them. This may continue until perhaps the more benevolent of the party engages in charity work around town to let the new wealth to the party sit a little easier with the locals.
Just because the boss is dead, doesn't mean the adventure is over. Getting the treasure home is not just "tedious book keeping", it's a roleplaying opportunity. If someone sitting at your gaming table today suddenly won the lottery for $300 million, it might change the interactions that follow at the next session. The same would be true in a fantasy, medieval-based, town. Of courses tax collectors and nobles will start snooping around. But that's also another post not about carrying stuff home.
There is often overlooked treasure in the game that enterprising players will discover and you as GM should be ready to handle. 20 kobolds attacked and defeated? great! is that 20 short swords and 10 short bows with arrows? Maybe a dozen daggers?
Even junky kobold short swords are worth something. I've had players make stashes of these and keep notes to return later. A shoddy shortbow might only be worth a half a gold, and 20 short swords only a gold a piece. Over the course of a few sessions though, that character has flooded the market with weapons and goods, and their pockets with coin, and of course, their XP. In this regard, I am a fan of individual XP and not benchmarks. One player fiddling with this, hiding things and returning later, earns the reward. If the whole party helps, then that's group XP.
Those swords, and armor parts all weigh up though. Loose attention to how bulky and how much everything weighs is important, but it doesn't need to dominate the session.