My plucky players have entered a megadungeon in the vain hopes of escaping the mind racking adventures of the surface world (the fools!). This opens all sorts of interesting things to mess with based on extended periods spent underground, away from civilisation. Like weapon fatigue, something I've quite fancied for a while.
In real life swords are pretty delicate things, maybe surviving a couple of intense battles before needing a good seeing to. Spearheads come loose, polearms snap, knives bend, clubs splinter &c.
Every time you roll a 1 the die size of your weapon drops. So, a typical sword on rolling its first 1 will fall from d8 to d6. This goes all the way down to d3, where you are reduced to a heavy nub with which to assail the enemy, though rendering pitying looks rather than blood and bruises. Up until this unhappy point it is fixable. Lamentations' rules of "bigger weapon, bigger dice" works very nicely with this, simulating a longer period of usefulness in larger weapons that have more to fall apart. A polearm without a head is still a big stick, after all.
Similarly, by design armour takes a pounding. When a 20 is rolled against you, your armour drops by increments of 1 until it falls apart. Up until that point it can be repaired and patched quite happily.
So, repairs. It will take 10% (modified by local market trends) of the item's value to repair an increment. A sword worth 100 silver pieces that has gone from d8 to d4 would cost 20 silver to repair. While on the road a character that has suitable equipment (whetstone, nails, needle & thread, whatever makes sense) may repair one increment of damage sustained that day.
This system shouldn't be symmetrical. Enemies aren't around long enough and are too varied to make proper use of these rules. Instead, keep a tally per game of how many times you've rolled a 1 for non-players' attacks. Every 4th (5th? 3rd?) 1 rolled will result in that fellow breaking their weapon. As for players rolling 20s, a 20 is its own reward but you could potentially apply the same system: every Nth roll shatters some armour.
I suggest varying the increments each game, possibly going so far as to roll it randomly so as to keep the players from being tempted to count them.
Shields, of course. Shields.
If you have a shield you can ignore armour fatigue, however at the end of the fight there is a 1 in 3 chance that the shield is knackered beyond use.
Entirely unrelated point:
If you don't know why a location is named the way it is then it probably shouldn't be named as such. The people living there don't need to know, but you should. In countries that have existed for more the a few generations place names are very literal and locals are usually aware of the history.