Ykhjuy

I haven't played D&D for a while though recently I have started playing it with my kids. The group is made out of five. So far they have acted with wisdom and they have been lucky which allowed them to slay a Thundertree Green Dragon. Are there any rules for disassembling the dragon for the sake of doing things such as selling its meat and making armor from its scales?

There are no specific rules for disassembling a dragon or other creature to sell its meat or make armor from its scales.

Your mention of Thundertree leads me to guess that you're playing The Lost Mine of Phandelver, which implies a setting of The Forgotten Realms -- although not necessarily, you could forklift LMP into your own world and I am sure many do, and even if you want to remain as close to the default setting as possible, you end up having to make choices about how things work in your game.

I am not aware of any reference in 5E materials suggesting that the sale or consumption of dragon meat is a common, or even rare, thing.

There is official dragon scale mail armor, so it's reasonable such a thing could exist in your world. Making armor is a skilled activity, so maybe your characters have that skill, or maybe they don't. Maybe they need to find an armorer. Maybe any skilled armorer could make it, or maybe there's only one armorer in the entire world who knows how to make dragon scale armor. XGE has optional rules that suggest crafting a very rare magic item would take 25 weeks and 20,000 gold, but it's up to you whether you consider that as reasonable in this case.

There are a lot of maybes because this specific situation is not specifically accounted for in the rules. However, there is always the basic rule of D&D:

1. The DM describes the environment.


2. The players describe what they want to do.


3. The DM narrates the results of the adventurers’ actions.

It's perfectly reasonable for the DM to say, "Okay, you've got a dead dragon", and for the players to then say, "Can we butcher it and sell it?"

Then, you as the DM need to decide what you want to do at that point. You can deal with it as simply as "Yes, you're able to sell some meat and scales for a 1000 gold", or "No one wants dragon meat, ewww, but the armorer in the nearby town will make you a nifty set of dragonscale armor if he can keep the rest of the scales." Or whatever you want. You can make dining on dragon meat to be the height of haute cuisine, or taboo, or anything in between. You can spend a great deal of time focusing on what to do with the dragon carcass, or you can dispense with it quickly and move on to something else.

Good luck!