Cosmic Encounter - Gameplay

Gameplay

Cosmic Encounter is based on a fixed set of rules which are subsequently modified by other elements of the game.

Each player begins with a color-coded "home system" containing five planets, and twenty tokens representing starships that populate these planets as bases. A central "Warp" is used to place defeated ships for all players. The game goal, in general, is to occupy five bases on planets outside one's home system. The player is dealt a hand of seven cards from the normal card deck, which includes three types of cards normally. Two types are Encounter cards, including numbered Attack cards and Compromise/Negotiation cards, while the third type are "edicts"/"artifacts".

On a player's turn, they retrieve one ship from the Warp, and then turn a card on a second deck, the color-coded "Destiny" deck, indicating which system they must attack. Using a special "attack cone" indicator, the player selects which opponent on which planet to attack, and then places from 1 to 4 ships on the cone. Both the attacker and defender can ask the other players individually to ally with their side, committing up to 4 ships on either side of the conflict.

Once allies have committed to the combat, the attacker and defender select an "Encounter" card, which is either a numbered Attack card, or a Compromise/Negotiation card. If both cards are Attack cards, the total of the attack value and number of allied ships are added for both sides, and the side with the larger value wins with the defending player winning in case of ties. If the attacking side wins, the defender's base is lost and all ships and allies' ships are sent to the Warp, while the attacker and their allies gain the base on that planet. If the defending side wins, the attacker and allies' ships are sent to the Warp, and defending allies gain a bonus of either a ship from the warp or a new card for each ship risked. If one side plays a Compromise card against a numbered card, they immediately lose, but they, though not their allies, get "compensation" from the victor such as by drawing cards from the victor's hand. If both players use Compromise cards, they have one minute to make a deal, such as exchanging bases, while all allies are sent back to their respective bases. If a deal can't be made, both players lose ships. The player then draws a card and play proceeds to the next player.

To aid in timing, each turn is broken down into a number of phases, and cards and powers will typically indicate which phases the game elements can be played in. In particular, the edicts/artifacts cards, which generate an immediate effect such as releasing all tokens from the Warp, may only be played during specific phases which will be listed on the card, while certain features of alien powers can only be triggered in specific phases.

The game becomes complex with the introduction of alien powers. These are typically drawn randomly at the start of the game and known to all players; however, variants exist where players can select their powers, use multiple powers simultaneously, or hide their powers until they are used. Each power gives the player a way to bend the core rules to their advantages, typically in one of the following ways:

• Continuous effects, such as the Macron where each ship is valued as 4 ships
• Combat resolution effects, such as the Void where any ship that loses against it is pulled from the game instead of going to the Warp
• Victory condition changes, such as Masochist that wins if it loses all its ships
• Role-playing elements, such as the Sniveler, where the player, if they are in the losing position, must whine to the other players to gain benefits.

A player's alien power is only active if they control three or more bases in their home system, and if lost, can be regained by taken back a third base.

More advanced optional game components can add further levels of complexity and unpredictability. No edition has all of the optional components. They include:

• Flares: Cards that grant a limited version of an alien power, or, if used by the player that possesses that power, a significant advantageous gain.
• Lucre: In-game currency that allows more control of resources (such as buying more cards for one's hand). Multiple alien powers affect Lucre.
• Moons: Colonies on moons do not count towards victory conditions, but occupying one grants access to its special ability. Moon abilities can be powerful (such as retaining an alien power when it would normally be lost), while others are best described as "silly" (such as forcing the owner to speak in rhyme).
• Special planetary systems: Printed on the reverse side of the normal systems in most prints of Cosmic Encounter, the special systems have additional rules in regards to the player's initial setup, colonies, and victory conditions.
• Technologies: An array of boosts and special abilities, none of which can be used right away. Technology cards are placed face down on the table. The owner may move one ship from a planet onto the card at the start of any player's turn. Once the number of ships on the card meets the card's cost, technology is "discovered," the ships return, and the card is flipped face up. The power of technology cards varies wildly. The Xenon lasers card costs two ships, and its owner may change encounter scores by one point. The Omega missile card costs eight ships, and destroys a planet.
• Rewards: A deck's worth of incentives, reward cards can only be drawn by victorious defensive allies. Reward cards include "kickers," multipliers for encounter cards, and "rifts," booby traps that free ships from the warp, or send ships there if they ever change hands.

Some players have created their own "homemade" powers, and have posted these along with other various game extensions on the Internet.

Major variants include multiple-power games (in which players have multiple alien powers at once) and hidden-power games (in which powers are not revealed until their first use). Official variants include rules for adding a seventh or eighth player, and there has been a version providing enough components for a ten-player game (when combined with a previous release).