What You Need Overview
In the game of Homeworlds, you take on the role of a space-faring civilization that's become embroiled in an epic, galaxy-wide struggle between Good and Evil. Good civilizations try to work together to eradicate Evil, while Evil civilizations crave only senseless destruction. But which players are Good and which are Evil? That's the ultimate question in this game of strategy, psychology, and diplomacy.

Good and Evil
Before the game begins, each player's secret alignment must be established. Gather a handful of cards or markers that you can use to represent the alignments of Good and Evil. (If you use a deck of standard playing cards, hearts can represent Good and spades can represent Evil.) The number of cards that you gather should be equal to the total number of players. If there is an even number of players, half of the cards should be Good and the other half Evil; if there is an odd number of players, there should be one more Good card than there are Evil cards. Mix up the cards and give one to each player.

You may look at your own alignment card, but you may not reveal it to any other player, except in the special circumstances outlined later in these rules. You're allowed to say whatever you'd like about your own alignment, or about what you think another player's alignment might be, as long as you never actually show your card. You're also allowed to make any in-game deals you'd like with other players, but these deals are never binding.

Setting Up Your Homeworld
After the secret alignments have been established, randomly choose a starting player. Play begins with that player and moves clockwise around the table. On your first turn, you must set up your Homeworld. Select any two pieces of any sizes and colors to represent your Homeworld, and a third piece of any size and color to represent your first starship. Place your two Homeworld pieces in an upright stack in front of you. (If one is smaller than the other, put the smaller one on top so it's easier to see.) Place your ship near your Homeworld, lying down and pointing directly away from you.

Star-Systems and Starships
During the game, upright pieces will represent star-systems, and pieces that are lying down will represent starships that occupy these systems. The upright pieces are referred to as "system markers". Your Homeworld is a binary star-system, so it's represented by two system markers. As the game progresses, players will discover and travel to other star systems; these systems will all be single-star systems, which means that each one will be represented by a single system marker.

The color of a system marker represents a technology that's available to be used in that system. The size of a system marker determines how that system is connected to other systems. Starships travel from system to system using wormhole connections through space-time. Two systems are connected to each other if they do not share the same size system markers. If two systems contain the same size system marker, those two systems are not connected. Therefore, a small system is connected to any medium or large system, but not to another small system. A binary system made up of a small piece and a medium piece is not connected to any small or medium system, nor is it connected to any binary system that contains a small piece or a medium piece. System connections have nothing to do with the physical positions of systems on the playing field.

Pieces that are lying down near a system marker represent starships that occupy that system. If a system does not contain at least one ship, it no longer lies within "known space"; immediately return the system's markers to the global stash.

The direction that a ship points indicates who owns it; a ship is always pointed directly away from its owner. You must always own at least one ship in your Homeworld; if at some point you don't own any ships in your Homeworld, your civilization is destroyed, and you are eliminated from the game. If you are Good, the object of the game is to eliminate all of the Evil players. If you are Evil, the object of the game is simply to eliminate any other player.

On your turn, do one of these three things: perform a single free action in a system that you occupy, sacrifice one of your ships to take a certain number of actions of that ship's color, or take no action at all. After you do one of these three things, you may trigger catastrophes for any overpopulations that exist.

Free Actions
When you choose to perform a single free action in a system that you occupy, you may use the power of any technology (color) that's available to you in that system. The colors that are available to you are determined by the colors of all of your ships in the system, as well as by the colors of the system's marker(s). The technological powers are as follows:

Note that you can apply any action to pieces of any color, as long as you have access in the system to the color of the action you wish to perform. For instance, you can move any one of your ships out of a system as long as you own at least one yellow ship in that system, or the system itself contains a yellow marker.

Sacrifice Actions
Instead of performing a single free action, you may sacrifice any one of your ships to perform a certain number of actions of that ship's color. To sacrifice a ship, simply return it to the global stash. You may then perform the number of actions determined by the size of your sacrifice ship - one action for a small piece, two for a medium piece, and three for a large piece. The type of action you're allowed to perform is determined by the color of the sacrifice ship; if you sacrifice a red ship, you're only allowed to perform attack actions. Each action may be performed in any system you occupy, even if you don't have access to that color in that system. Sacrificing a ship gives you temporary access to that color in any system you occupy. The sacrifice actions are always optional.

Overpopulation and Catastrophes
If a system contains four or more pieces of the same color (including system markers and ships of any ownership), that system contains an overpopulation of that color. At the end of your turn, you may trigger catastrophes for any overpopulations that exist on the board, regardless of where they are or who owns the ships in them. To trigger a catastrophe, remove all of the pieces of that color from the system (including system markers), and return the pieces to the global stash. If you remove a system marker from a binary system, the system becomes a single-star system. (This may cause the system to become connected to more systems.) If you remove the system marker from a single-star system, the system itself is destroyed, and all of the ships in it are returned to the global stash. Triggering a catastrophe for any given overpopulation is always optional, but if you do choose to trigger it, you must remove all of the pieces causing the overpopulation.

Elimination and Winning
As previously noted, you must always own at least one ship in your Homeworld; if at some point you don't own any ships in your Homeworld, you are eliminated from the game.

You are never allowed to take an action or trigger a catastrophe that causes you to own no ships in your Homeworld at the end of your turn. You may temporarily abandon your Homeworld during your turn, as long as you own at least one ship in it at the end of your turn.

If you ever take an action or trigger a catastrophe that causes another player to own no ships in his or her Homeworld, you have eliminated that player from the game. (It is possible, though difficult, to eliminate multiple players on the same turn.) At the end of your turn, if you've eliminated someone, reveal your secret alignment (if you haven't already); any players that you eliminated should also reveal their alignments (if they haven't already). If you are Evil, you win the game immediately. If you are Good, check to see if there are any Evil players left in the game. (You can determine this by looking at all of the alignments revealed so far.) If there are no Evil players left, the game ends immediately, and all of the remaining Good players share the win. Otherwise, the game continues. An eliminated player's ships are not automatically removed from the board; they remain to be captured by other players or destroyed in catastrophes.