Possible concepts for either a 3rd xpac or Civ 6 VP, concerning the expansion of current combat systems, to make warfare itself more tactically demanding 1. Unit differentiation Historically many units were better at attacking enemy positions rather then holding their own. Therefore all melee units should have separated attack and defence CS's (e.g. The anti-cav lines have lower attack, higher defence, whilst cavalry lines have higher attack, lower defence) This means that you have to train a wider variety of units to suit your needs. As an extension of this, it would be cool to give unit different levels of Hit Points, so Knights might have 115 HP, and Scouts might have only 80 HP. Once again, making each unit more unique. 2. Supporting units Currently units each have a certain maintenance cost in Gold, and will consume some strategic resources with GS, but that's it for support. A return of the Unit Supply cap from Civ 5 VP could help, representing the total amount of soldiers your empire can support before resources are exhausted (causing decreased CS in all units, and empire-wide loss of amenities). The supply cap could be increased by your empire's total number of Citizens, Encampment districts and military training buildings. (Another reason to go tall over wide at the moment). 3. Bringing back the stack When warring against enemy civs, 1upt can be really tedious, especially when you have like 40 units to move per turn. Civ 6 has improved with support units and Corps/Armies, but this isn't really a full solution. The problem is, the cheerfully named 'stack of doom' is easy to troll with, so the idea is to return to stack with limitations. In the Stone Age, organized and structured armies were non-existent, you just had a band of warriors with stone clubs attack another band, so start with 1upt. With the discovery Military Tactics you can stack 2 units per hex, then in the Industrial Era with Military Science, it becomes 3upt. Finally in the Atomic era with Combined Arms, it rises to 4upt. There are many ways this could integrate with combat mechanics. Light cavalry units are so mobile they could attack any unit in a stack, and ranged attacks on stacks deal lighter damage to every unit within the stack. Additionally, the limit of civilian units per hex would be infinite. 4. Keeping morale high Another concept I wanted to emphasize is the need to keep your troops happy during war. Each unit could have a separate Morale score, representing their fighting spirit, that would increase or decrease with certain conditions. (e.g. little/lots of wounded or dead troops, recently won/lost battles, being close to/far from friendly territory, overworked by too many recent engagements, the war going well/badly in general, surrounded by ally/enemy troops, having a nearby friendly/enemy Great General/Admiral, and so on) Poor Morale could lead to lowered CS for that unit, or even whole units deserting and turning barbarian. Interested to see if the community has any further thoughts/ideas, all are welcome, and sorry if this is a bit of a wall of text.