Rolemaster solved this circa 1980.
Both combatants have an Offensive Bonus (OB) resulting from their skill, strength, positional advantage, etc. At the start of the round each combatant decides how much of their OB they use to attack and how much they hold back as a Defensive Bonus (DB) that subtracts from incoming attacks.
Some editions have a similar decision point regarding Initiative where you can act quickly at -20, act normally at +0, or act slowly at +10.
When you attack someone you roll d100, add your OB and other bonuses, and subtract their DB and other penalties.
The real innovation is that you compare your result on a table. Each weapon has its own table (like broadswords and shortswords and scimitars and daggers are all different full-page tables). There are 20 Armour Types, from AT1 (nothing) tthrough leathers and chain to AT20 full plate. Each one is a separate column on the table. The results on the table determine whether it's a hit, how much hit point damage it causes, and what kind of critical table you roll on. Rolemaster characters generally have a lot more hit points and it's the critical hit tables that create the deaths and maimings.
What this means is that some armour types (like AT1) have more total misses (you are better able to dodge) but when you do get hit, it might be 20 hit points damage and a nasty crit. If you're in leather you are a bit easier to hit but the armour soaks up some of the damage so you lose less hit points and get reduced crit levels. If you're in chain or plate you are even easier to hit again but a lot more attacks that would have been nasty crits against AT1 are reduced to just hit point damage or lesser crit effects.
These tables are different for each weapon so slashing weapons might be even worse against plate while piercing weapons are even better against leather.
It seems very complex, and has a reputation for being complex, but as long as you can do a bit of addition I would say it's less complex than most modern editions of D&D. The tables do a lot of the heavy lifting.