A few rules I have toyed with or implemented for a more enjoyable or more interesting game. Feel free to comment or add your own.

Cooperative Transfer

As an action, similar to the Transfer action, activate a system containing another (willing) player's ships, with whom you have a Trade Agreement, using a Command Counter. That player then activates an adjacent system containing your ships using a Command Counter from his reinforcements. Switch all ships on these two systems, including Space Docks, if able. Planetary Landings and Production may not be performed during this action, but movement may provoke PDS fire.

Politics Variations

If a card is drawn and requires players to elect one [Law, Player, Planet, etc.] in which there is only one of these things to elect, players may choose to put their votes towards NOT electing that item. For example, if a card is drawn to repeal a current law, players may vote against repealing the only law in play.

When players are called to vote or elect, allow some time for players to mingle and leave the room if necessary. This will allow time for voting conspiracy to form, and players' votes to be bought. When it comes time to vote, they each write their votes down in secret and reveal them simultaneously. This variant is for players who prefer 'straight-up' politics as it avoids "vote stacking", wherein players vote to deliberately topple the natural order.

Setup Variations

Before removing any game tiles from the pile, remove all wormhole tiles. Shuffle the remaining tiles and remove tiles as necessary. Add the wormhole tiles back in, shuffle and deal. In this variant, all wormholes will be placed on the board. Optionally, players may choose to remove the Keeper of Gates Secret Objective.

We always use all wormhole tiles in my playgroup. That is a great houserule/variant to use.

We also keep Keeper of the Gates in as you will have every wormhole in play and the objective should be much more difficult to accomplish with all wormholes in play.

Zen said:

This variant is sort of already incorporated in the options available of the standard rules. Any player may abstain to vote.

While this is true, and any individual player CAN abstain (not vote), if it's a vote like an "Elect Player" or "Elect Law" or something where you choose something, in the end the vote DOES have to have some elected player/law/whatever. Even if everyone abstains, the Speaker, by rule, is forced to break the tie vote, and breaking the vote means that something has to be elected.

The only way to prevent such a law from taking effect is via a Veto card (or the Xxcha ability to veto).