This is a shameless self-plug; I've made a couple of diagrams I consider very useful, and I wanted to share them with this community, since I could have used them when I started playing. The first diagram shows a summary of what unit upgrades to what unit, and includes all the UUs. There's also a GaK version available, which also takes into consideration special upgrade paths (e.g. Dromon). Also up now is a BNW version, again with all UUs and their special upgrade paths. The second diagram shows a summary of what are the requirements for the various promotions. Again, I will attempt to keep it updated with future patches. Moderator Action: A version of the promotion chart for 18.104.22.1681 can be found here.