[RPG] Can a fighter learn to use firearms despite them only recently being invented by another member of the party

artificerdnd-5efighterfirearms

Recently, after one of our PC's fell off a mountain we welcomed a new fighter to our party, hailing from a far-off land.

Our party is all level 3. I'm playing a dwarf artillerist artificer. My character is the only person (that we know of) to have invented firearms. Given their novelty and effectiveness of my weapons our new fighter PC has taken interest in my inventions, and after saving me from a particularly nasty encounter I decided to gift him my backup pistol as a token of thanks.

However, this raises the question:

Does our fighter have proficiency with the firearm I just gave him?

The PHB lists fighters having proficiency with all simple and martial weapons. So by the book he would have proficiency the moment he starts using it. Understandably, however my DM has ruled them to be "Too New" and that I will have to train with our fighter for some time before he has proficiency.

What would be a good way to quantify training with such an item? How long would it take for our fighter to learn how to use this gun? Are there any benefits that me being an artificer would bring to the table?

For reference, I gave him a palm pistol that uses these stats.

The damage isn't high enough to outclass any of his other abilities (he's a samurai lol) but outside the game he does want some ranged capacity.

Best Answer

This is entirely up to your DM.

You answered your question when you wrote:

Understandably, however my DM has ruled them to be "Too New" and that I will have to train with our fighter for some time before he has proficiency.

The Dungeon Master’s Guide has a section on firearms:

It’s up to you [meaning the DM] to decide whether a character has proficiency with a firearm. Characters in most D&D worlds wouldn’t have such proficiency. During their downtime, characters can use the training rules in the Player’s Handbook to acquire proficiency, assuming that they have enough ammunition to keep the weapons working while mastering their use.

And the mentioned training rules from the Player Handbook state:

You can spend time between adventures learning a new language or training with a set of tools. Your DM might allow additional training options.

First, you must find an instructor willing to teach you. The DM determines how long it takes, and whether one or more ability checks are required.

The training lasts for 250 days and costs 1 gp per day. After you spend the requisite amount of time and money, you learn the new language or gain proficiency with the new tool.

All of this is entirely up to the DM. You will have to ask then how long it will take, what you will have to do, and if there is anything you can do to speed up that process to get your friend trained to be proficient with firearms. The rules for firearms are DM-facing, not player-facing, meaning they are presented first to the DM as an entirely optional rule set to be implemented at their discretion.

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