[RPG] the purpose of having proficiency with artisan’s tools


One of my players wants to build a forge (see How much gold would the construction of a forge cost?).

I explained to him how the creation of a magic item works (like a +1 weapon, for example), and he asked me how his proficiency with smith's tools was supposed to help him.

Well, the PHB p.154 says the following:

Proficiency with a set of artisan’s tools lets you add your proficiency bonus to any ability checks you make using the tools in your craft.

But crafting a magic item doesn't require any ability check!

So my question is, what is the purpose of having proficiency with artisan's tools?
And more specifically with smith's tools?

Best Answer

For crafting non-magical items.

From the Downtime Activities on page 187 of the PHB:


You must be proficient with tools related to the object you are trying to create (typically artisan’s tools). [...] For example, someone proficient with smith’s tools needs a forge in order to craft a sword or suit of armor.

So RAW it would appear that crafting doesn't actually require any ability checks. You just need proficiency in artisan's tools to be able to craft non-magical items in the first place.

But the DM might call for other ability checks that require artisan's tools.

From page 154 of the PHB:

A tool helps you to do something you couldn't otherwise do, such as craft or repair an item [...] For example, the DM might ask you to make a Dexterity check to carve a fine detail with your woodcarver’s tools, or a Strength check to make something out of particularly hard wood.