Fire Emblem Knave

I was going to do Knavely Default but then Fire Emblem happened so fuck me I guess.

The Weapon Triangle

If you know anything about Fire Emblem other than Marth being in Smash, you know that Swords beat Axes, Axes beat Lances, and Lances beat Swords. This is very important in the games, so let's give advantage to the unit who has advantage and disadvantage to the unit with disadvantage. We should also restrict weapon proficiency to prevent having every unit just swap weapons at will. I would just have a character start out knowing how to use one weapon type at Iron level and another on Bronze unless you want to start with a legendary weapon. More on that...

Weapon Concerns

Weapons are classified by quality and usually fit into Bronze, Iron, Steel, and Silver (from lowest to highest). Lower quality weapons are usually faster and/or more durable but better weapons deal more damage.  Practically speaking, we want to use the better weapon unless we want to get more granular, so let's just say you have Bronze deal d4, Iron deal d6, Steel deal d8, and Silver deal d10. Special weapons, like legendary blades can deal d12 damage.

To increase your proficiency in a weapon, just score a number of critical hits with that weapon equal to half the maximum die roll of the current level (so 2 for Iron, 3 for Steel, and 4 for Silver), counting from scratch each time your proficiency goes up.

Quality is great for emulating durability, so let's keep those rules. All weapons take one slot and have 3 quality.

Other Combat Factors

There are other Fire Emblem things, like using a grid for combat and archers having less range because otherwise they'd be super OP, but we're mostly ignoring that here.

Combat is in turns. Using Knave initiative is good because it uses block combat, which matches up pretty well.

There are some units that are just straight up counters. For example, archers will do massive damage to flying units. Just triple your damage die count and you're good.

Spellbooks are just a different type of weapon. Just flavor them as you'd like and apply the weapon rules.

My Units and Classes

To make units, either make a bunch of PCs and have them level up a couple of times, or do whatever. It largely depends on the game. Players might want to play multiple characters, and that's fine. I'm not going to define any classes right now, so again, do whatever.