My friends and I have been playing DnD 5e for a few years now, but now I’ve decided to start GMing PathFinder 2e. We’ve played through most of the Beginner Box, and now I want to continue with my own homebrew content. As part of my world, I want to introduce a fighter “subclass” (probably the wrong terminology for PathFinder). What I want is a tribe of warriors who fight without armor (starting at level 2 or 3), and to compensate for the lower AC they get magical tattoos which increase their AC. It will also be possible (when you advance in levels) to choose to add other tattoos with other magical effects.
So my question is: Is this what archetypes are for? Because I don’t think “subclasses” are a thing in PathFinder? Or how would I go about this?
Some classes have something akin to sub-classes. Rogues have Rackets. Druids have Orders. Clerics have their gods. Wizards have Schools. These additional class feature choices do anything from giving you different bonuses and proficiences, like in 5e, to offering up different starting spells, like with Wizard schools.
But yeah, most of the focus, both from the core designers, and 3rd parties, is on archetypes for creating different permutations of a given class. People don't like to touch the underlying class chassis.
Rules exist around characters crafting magical tattoos in the game (found in Secrets of Magic, Pg. 164), but there doesn't seem to be much guidance for GMs trying to design their own.
Most of the tattoos that have been published have active effects that can only be used once per day, in addition to a passive boost to some skill.
I assume you have a wider vision for this that could necessitate an actual archetype, but just based on what you've shared here, I think you can get what you want just by designing some tattoos that give passive improvements to AC when the bearer is unarmored. If you want to go the full archetype route, you can specify that the tattoos only work on characters with that archetype dedication.
Now that you mention it, just creating an "item" that is effectively just an armor flavored as tattoos has its own advantages.
For example, at higher levels the character could apply armor runes directly to their body. Thats pretty cool in and of itself and also in tune with the idea of expanding the tattoo with different effects. All with minimal effort and without having to worry about balancing issues because the rules are already there.
Flavouring an item would also open up making it a relic, which could be fun.