If a treasure trove contains a pile of coins (just scattered on the floor), at what rate could a character realistically pick up these coins to add to their collection?

Usually in these situations I just hand-wave these sorts of interactions away, but I am trying to come up with a dungeon where time is of the essence. If the party spends too much time picking up coins, they may lose out on other possible achievements or reaching their final goal.

Depending on the size of the hoard, it would depend...a person could probably scoop 5-10 pounds of material into a bag in a couple of seconds (250-500 coins) if the pile was in one place and sizable.  Picking up individual coins spread out would be much slower, probably a coin per second with no other actions or distractions if the person didn’t have to move much

it’s going to depend on how spread out they are, of course, but It’s D&D, roll for it. something like a d10 per round. Or a d12, cause any excuse to use a d12 is good. The more you want them to be able to get, the bigger the die you roll. Could add dex mod, since it seems like dex based, but just a straight roll could work. 

Would also depend on how you're considering time to be a factor? In terms of rounds, or minutes, etc.? I'd likely just ask the party what they think. Something like "it'd likely take a half hour to collect all of the scattered coins. But, Because time is of the essence, how would you all propose dealing with these coins but keeping in mind there's only about 15 seconds before the teleportation gate closes / roof collapses / bomb explodes?"

Answers could include one player saying they'd like to use their shovel to grab a few scoops at random (Dex) , another might say they'd prefer to give a quick glance (perception, intelligence, wisdom) at the scatter to determine where most of the gold is which could yield more value but only taking one scoop, another might just say they'd scream at everyone to just grab and go quickly (intimidation/charisma). Let the party determine a method, any skill settled upon can just be considered a singular (or group?) skill check roll with ordinary modifiers, with a DC determined on the fly with how you personally strong you feel the suggestion to be.  And adjudicate a sensible yield (xd20 or so of each coin value).

To add a bit more detail:

1) For the room the coins are scattered in, there is more or less a thin layer on the ground, no big piles but enough that people walking across could risk slipping and falling on them. 

2) I am considering this all for a one-shot I am writing where the players are conducting a heist. Their goal is to amass a large amount of wealth from this place, but I am going to implement a real world time limit (since it is a one shot) to make things more difficult. Ultimatley, if the party decides to dedicate time to picking up the coins, it could be described briefly by the DM but then there would be a reduction to the timer to reflect the time they had to spend to pick up all the coins.

3) I was planning on having them have the option of clearing coins from 5 foot squares in the room at a time, with each square having about 100 SP scattered around, and each square taking some finite amount of time to clear (1 action, 1 minute, etc) to collect all the coins 

Here's what I would do if this came up in my own campaign...

I'd have any player who wanted to pick up coins scattered across the floor use their action to make a Sleight of Hand check. Whatever roll they make on the check is how many coins they grab. Maybe give disadvantage if someone is wearing gauntlets. A dexterous rogue with expertise might come out with a metric buttload of coins, but that's their reward for investing in sleight of hand so thoroughly. Each check represents six seconds of time, essentially treating it as a turn in combat. If the player wants to spend a minute picking up coins, just take that same roll and multiply it by ten.

Quote from TransmorpherDDS >>

Here's what I would do if this came up in my own campaign...

I'd have any player who wanted to pick up coins scattered across the floor use their action to make a Sleight of Hand check. Whatever roll they make on the check is how many coins they grab. Maybe give disadvantage if someone is wearing gauntlets. A dexterous rogue with expertise might come out with a metric buttload of coins, but that's their reward for investing in sleight of hand so thoroughly. Each check represents six seconds of time, essentially treating it as a turn in combat. If the player wants to spend a minute picking up coins, just take that same roll and multiply it by ten.

 Thats not a bad idea. I do like the idea of it rewarding a player investing in using their hands quickly. Still, these coins also act as a hazard (like thin ice), so grabbing 5-6 coins probably wouldn't be enough to undo the hazard. That could maybe be fixed by simply stating "if X number of coins are taken from a space, it is no longer treated as a hazard" or something similar 

Oh, that's interesting... I'd say think of it as essentially being the DC needed to "disarm" the hazard the coins create. If you want it to be something fairly simple such that any player in the party has a decent chance of clearing any given 5 foot space, then make it only 10 coins, 15 for a greater challenge, etc., etc.

Quote from TransmorpherDDS >>

Oh, that's interesting... I'd say think of it as essentially being the DC needed to "disarm" the hazard the coins create. If you want it to be something fairly simple such that any player in the party has a decent chance of clearing any given 5 foot space, then make it only 10 coins, 15 for a greater challenge, etc., etc.

 That could work, although im not sure 10 or 15 coins spread across a 5 foot square is really enough to slip on.

Yeah, I have to admit, the two systems aren't quite meshing now that you mention it. Maybe you could treat it as the player successfully picks up 10 coins, but in the process scatters the remaining coins in the space enough to make it safe to traverse.

Quote from TransmorpherDDS >>

Yeah, I have to admit, the two systems aren't quite meshing now that you mention it. Maybe you could treat it as the player successfully picks up 10 coins, but in the process scatters the remaining coins in the space enough to make it safe to traverse.

 That could work. I was planning on allowing the players to use their action to push the coins if all they wanted to do was clear the hazard without actually picking up any of the coins along the way. 

I think that's a great compromise! So any player not interested in coins is guaranteed the option to, at the very least, clear the hazard, but players that get greedy risk failing the task by focusing too much on gathering the coins instead of pushing them.

RAW, each coin is a Use Object interaction, unless you can come up with a mechanism that lets you scoop them, such as a broom.

Quote from Pantagruel666 >>

RAW, each coin is a Use Object interaction, unless you can come up with a mechanism that lets you scoop them, such as a broom.

 Technically, using a very strict interpretation of RAW, and assuming you are using combat initiative at the time, this is a RAW description of the mechanic. But the "use an object" action isn't really geared towards interacting with a larger number of small objects (there is precedent for this, consider whether you would require a "use an object" interaction to gather components for a spell from a component pouch, or gather the individual tools from a tool set to make a check)  Realistically, there are reasonable mechanics that could be homebrewed (drop prone + object interaction open bag + sweep mechanic (homebrewed sleight of hand check, no DC, check results = # of coins scooped up) that would be more realistic and more fun than "you can pick up two coins per turn (one free, one with your action)"