One of my favorite old-school RPGs. Destiny of an Emperor for NES. Basically it took the world of Romance of the 3 Kingdoms and made it into a traditional RPG
The thing that made it so unique, and SO hard is that what would be your hit points in a normal RPG is actually the number of troops in your generals army in this game. And the less troops you have, the less damage you do when you attack. So, initiative is HUGE, the person to go first in a battle has a HUGE advantage, because as soon as you remove some of the other players soldiers(HP), they are now doing proportionately less damage. This also makes difficult fights even more difficult, because not only is surviving when low on health hard, you're doing less damage to your opponent too. You can dig yourself into an insurmountable hole if you lose too many troops(HP) too early in a fight.
Also great is the fact that there are probably 20-30 characters in the game, which was an unheard of amount in the 8-bit era. Politics comes into play a lot(just like Destiny of an Emperor), you can steal another generals troops/commanders through bribery and coercion, sometimes even mid-battle. Of course, they can do the same to you too.
Also, a horribly difficult feature of the game is that you have to buy food for your generals/troops. The bigger your armies, the more food you need, and food is consumed with every step you take on the game map. So mindlessly wandering the map costs you money. If you run out of food, troops start to die(basically your HP slowly drains) and the game basically ends if you run out of food and money, you're stuck.