|Power of fortification|
|Builds citadels on planets|
As a main player or ally, after encounter cards are revealed, you may add 5 to the defense's total.
Your citadels may either add to or subtract from the defense's total when you activate them. Citadels are still discarded if the defense loses, even when they are used to subtract.
|Defending certain planets/colonies||Easily avoidable|
There are two primary parts to playing Citadel. The first is what kind of attack cards to use. Low attacks can be easily discarded, but they will have minimal effect - although in the late game with fewer ships around, they can become more powerful. High attacks have a significant effect, but then they will be unavailable to use as encounter cards, and opponents will avoid attacking highly-fortified planets unless Citadel is allied with them. Note that citadels are not discarded until activated and defeated - if Citadel wants to remove a certain attack card from the game, it can be placed on a planet and never activated.
The second part of Citadel is where to fortify. The simple path is to simply build up defenses on Citadel's home planets, making it easy to defend. It's also a good idea to put a pretty good citadel on foreign colonies, deterring opponents from picking them off. Citadels are also useful for protecting specific planets - for example, perhaps Virus has an empty home planet that's easy to take over; building a citadel there will make it more difficult for opponents to get a free colony.
Citadel can affect alliances rather significantly. It can bargain with the defense for an invitation ("I'll only activate the citadels if you invite me"), and the offense will tend to extend invitations in hopes of not having to deal with the fortifications.
Attacking citadel-less planets is a simple way to avoid Citadel in the early going, but as the game goes on, Citadel gets stronger, more influential, and more difficult to avoid. An early start is important for this reason.
Citadel's ability to protect specific planets can help against aliens such as Locust and Parasite, who are often very deliberate about what planets they choose to attack. The general defensive ability is comparable to a midgame Warrior or Chosen. However, Spiff, Loser, and Anti-Matter will all target fortified planets, and possibly Virus as well.
|FFG||You have the power of Fortification. During each player’s turn, after destiny is drawn, you may play an attack card from your hand faceup next to any planet in any system as a citadel. If a planet with one or more citadels is attacked, after encounter cards are selected, but before they are revealed, you may use this power to activate all citadels on the planet. If so, add their combined value to the defense’s total for the encounter. If you activate your citadels on a planet and the defense loses the encounter, discard the citadels. If the defense wins or you do not activate the citadels, they stay in place.||Brilliant architects who obsessively build vast fortresses as they travel throughout the Cosmos, the Citadels are often welcomed with open arms by the other races, who are delighted to benefit from the Universe’s best defenses. Of course, what the Citadels don’t tell them is that these fortifications only work when the Citadels want them to do so.|