Sadly, I don´t have a “real” solo variant, simply because the interesting thing is to see how all the civs develope and interact.
Most of these rules are just some ideas. I´ve played that game only twice, so it needs more testing. Feel free to leave your comments.
I play with 5 people. The first issue is to organize the players decks: I use a second table to place all the cards of all players, so that I can easily see them. I place the players cards in a row for each player but also in columns: for each phase of the game a specific column. So in this way, I can see with a single look, if any player is allowed to play a card in a specific phase and I don´t have to check every players deck all the time.
There´s a simple combat system by Jerry Hagen on BGG:
1. Calculate force strenghts as normal.
2. Draw one card for each player and add to that players combat strength.
3. Loser loses all units. Winner loses all units except for the difference in combat strenght / 2 (rounded up).
It´s fast and works really great!
You proceed on the Progress Track, even if you play the Wild chit.
Empires in a Dark Age only generate half their glory! (that should make the game faster, cause you simply will try to avoid staying in Dark Age.) That doesn´t apply for age 7.
When trading, players draw two cards. They halve their combined values (round up) and add that result to the card they played from their hand. In this way, solo trade is less predictable.
I was also considering that the player who plays a blue artifact should gain an extra point.
Also some event cards needed changing in solo play:
Rout: If an empire loses a battle, play that card. The winner may move into an adjacent area of that empire, if he has enough units left. He automatically wins that second conflict and loses no units.
High Command: Up to three units cannot be commited by the defender. There´ll be a second combat round against these units then.
I Spy: I can decide if the opponent has to draw a second card or not after I´ve seen the first card. The second card counts.