Did you ever had this feeling that the solution was right in front of you and never see it. That is exactly what happened to me yesterday. In fact, I am using a mechanic very similar to Eclipse, but even if I new and praised Eclipse rules many months ago, the following idea never came to my mind. Here is a quick description of mechanics:
There is 3 track from 1 to 5 (civil, military and empire). Each track has 4 tokens which leaves value 1 open. When you place a new city on the board, you take a token in one of the 3 tracks and place it on the board. Each turn, you will have the option to move 1 token between tracks in order to reorganise your development. So this is the core, which is very similar to eclipse, except that the city placement does not force you to take it from a specific track. As you expand, you levels increase.
Then, when you upgrade a city (flip the token on the board), you take a gold coin from another track. The gold coin increase any of the 3 track by 1 and these gold coins can be reassigned at the beginning of each turn. Unused coins go into the treasury which allows you to buy stuff (they are not spent, you only compare the price).
Now, what I have realised is that stronger empire will be more powerful. That contradict the original intention that the 3 tracks above are relative to each city instead of the whole empire. But it's true that a larger empire would make each individual city more powerful. So I added a few mechanics that might help counter balancing the "large empire are stronger" effect to make sure that smaler empires have good chances to survive.
Buildings: Player can build structure to compensate for what they lack. The number of buildings is fixed for all players what ever the amount of cities in play. So according to the empire's position, the building configuration will change.
Unrest: When adding gold to the system (city upgrade), sometimes you add unrest (marked on the gold track). There is a 5 level unrest track, when unrest is added, you add a token (power down) on one of the 3 tracks. In the end, you manage to convert 1 level into 1 gold which can also give 1 level. It's not really a penalty, but there might be unrest checks (roll <= unrest for revolt). Second, it would force larger empire player to use buildings that reduce unrest which smaller empire won't need.
Economy: The second way to balance large and small empire is that the gold is distributed between players according to their economic strength. Right now, economy would be measured by the variety/quantity of special resources the player have access to. So a player with strong economy could actually steal other player's gold coins. Giving a chance for smaller empires to get extra coins.
So this is the idea so far.
For the gold sharing, I am still trying to find a fast way to distribute the gold. The idea is simple, each resource has a number. So your economical power is equal to the total of these values. You might get bonuses if you have access to a lot of variety and if you have trade treaties.
So the gold of all players is pooled together and the players who are in the lead will get more coins. I was thinking of using a square triangle distribution like:
6-5-4-3-2-1-0-0-0-0
You would distribute the coins from top to bottom between players. NPC empire will count in the list so players are not only competing between themselves.
The problem is that distributing the tokens in different stacks every turn is actually a long painful process. Another idea is that a player could give 1 gold to each of the players above him. But the problem is that the gold is not cumulative. So if the economic situation change, redistributing the original gold and then re-balancing the gold would take a huge amount of time.
Else, I thought ranking could give a bonus, and everything else is shared evenly. So only a ranking card would move between players indicating the base gold they should have. Some buildings like a market place could say that you get 1 gold for sure.
So players would check hoe many gold they should have and then discard remaining gold in the pot. Then pot would shared evenly between players.
Do you have any other idea to resolve sharing resources between players in various amount.