Advanced war options
Warmongering in Civ3 is great but it could be much better and more realistic.
The only option you have when attacking the enemy in Civ3 is from the front. It's like two armys in the middle ages attacking each other until one army is gone. Battles should be more versatile. All units should be able to outflank enemy units, while fast units would have a better chance of doing this. Attacking an enemy unit from the behind should be devastating and not the same as attacking from the front. In Conquests, archers have bombard which is great. This thing should be upgraded somehow so that archers are used more often. One example could be that archers become longrange units. Different combinations of units should result in better defensive/offensive ability for the defender/attacker. All units could have "killing blow" option so that when you attack an enemy you should have a small chance to annihilate the enemy in the first round. This chance should increase when a unit becomes more experienced. "Killing blow" is just a name but why not call it "lucky blow" or something like that.
Then there is the UU. Some are great and some are not...
One UU is enough but different civs should still have different units. All civs should have more historically correct units. This means special: offensive, defensive and long distance units in every civ. One example could be that a swordman (3/2/1) in England could be an axeman in Scandinavia (4/1/1). Later on the game should be the same as now because technology in the real world is much the same all over the world. Everyone has tanks, planes, infantry and so on... This would make the game more challenging and different tactics would evolve for each new civ you play with.