rules of strategy games, post yours.
i have played my share of strategy games and for me there is one rule that if kept in mind when designing them makes great games. and that is that every choice should be a difficult one. such as choosing between 2 upgrades but having the one that you didn't pick be closed off to you(unless you get rid of the one upgrade and then you can rechoose). i think these difficult choices make you form specific strategies.
in elemental one of its weaknesses is that you can pretty much have anything you want. there are no real hard choices. some would say that choosing techs would be a hard choice, but with the many library resources in the game i always have tons of research early on. the same goes for other resources as well. i always find my self with thousands of unused materials.
so without making this post to long, post the design rules that you think the dev team and modders should keep in mind to make the game and their mods truly memorable.