Planetary invasion is the military method of capturing a planet. In order to execute a planetary invasion, a troop transport is required. A troop transport is a ship that has troops modules. To initiate the invasion, move the troop transport onto the planet. No invasion can take place if there are any enemy ships in orbit. Once the invasion begins, an advantage factor is calculated for both sides of the ground war. This number takes into account various factors, including quality of the soldiers, their courage, planetary defenses, and technology level. The invading force gets a 5 point advantage due to air superiority. The invading force can choose their preferred invasion tactic, which also affects the advantage factor. After all the choices are made, the potential advantage factors are displayed and will continue to fluctuate throughout their potential range until the invasion begins. After fighting begins, the advantage factors are locked down and both sides take casualties until there are no troops remaining for one of the forces. The remaining force has control of the planet.

Invasion PreparationEdit

Having an adequate number of troops ready beforehand can greatly shorten the length of a war and reduce losses by attrition.

A whole planet can be dedicated to produce troops: add morale buildings to reach 100% approval for a growth bonus, then add a ratio of fertility clinics and factories so that you can produce a transport in the same number of turns it takes to regrow the population used. If you end up with extra transports, you can always dump them on economy worlds to reach a high population quickly, or to help jump start new or captured colonies.

Invasion TacticsEdit

General note on invasion tacticsEdit

  • If they don't succeed, they don't cause ANY damage to the invaded planet. So when you have more troop transports and face a planet with large population, you can combine them: with initial troop tansport(s) you use the most destructive method (usually Mass drivers) to significantly increase your soldiering bonus and remove large chunk of defending population. Then you proceed with less destructive tactic, to reduce the chance of destroying buildings or decreasing planet's PQ.
  • In Dark Avatar and Twilight of the Arnor you can decrease population on a planet by planting spies on all farms. In the next turn the planet's population will be reduced to 6B (to 8B in ToA)(if you're invading a colony). Caveat: those spies may be neutralized, but pop will still be reduced.
  • In Dark Avatar and Twilight of the Arnor you can decrease approval on a planet by planting spies on all morale buildings. Then you need to select another planet, and select back the one with spies. Approval on it will be severely reduced, so you can use Information Warfare with greater chance of success. You can re-use those spies on another planet in the same turn.
  • An evil-aligned civilization can build No Mercy Invasion Center, that eliminates invasion costs.

Summary Edit

Tactic Tech Cost Bonus Planet Quality Drop Planetary Improvements Destroyed
Traditional Warfare None 0 0% 0% 0%
Mass Drivers Planetary Bombardment 200 +100-200% 10-50% 50-100%
Core Detonation Space Marines 250 -40-50% 10-30% 20-30%
Tidal Disruptors Tidal Disruption 200 -40-50% 0% 80-100%
Mini-Soldiers Shock Troops 500 +40-70% 0% 5-10%
Gas Warfare Planetary Invasion 200 -15-30% 5-20% 0%
Information Warfare Planetary Invasion 800 20-40% 0% 0%
  • Positive bonuses are applied to the attacker, negatives to the defender.
  • Information Warfare converts unhappy population.

Traditional WarfareEdit

  • Description: Using the troops on hand and the best military equipment available, we send our soldiers into battle the classic way. Our men won't receive any bonuses, but this is the safest way to attack without fear of damaging the worlds we are invading.
  • Note: the only one that's free. Use it when invading low-population planet, or your soldiering advantage is large.

Mass DriversEdit

  • Description: By attaching drive-thrusters to nearby asteroids, we'll be able to use the space boulders as large-scale projectile weapons. While the attack will be almost unstoppable, destruction on a planet-wide level is inevitable.
  • Cost: 200 BC
  • Bonus to Advantage factor: 100%~200%
  • Planet quality Drop: -10%~-50%
  • Planetary improvements Destroyed: 50%~100%
  • Use it when you have to reduce the defending populace, or when you already have a large empire and don't particularly need new building space.

Core DetonationEdit

  • Description: Before the attack begins, we'll send a crew down to the surface of the targeted planet. The group will equip a half-dozen mining vehicles with Illudium Lite explosives and direct them at the core of each planet. This will cause a planet-shattering explosion that should significantly weaken the enemy defenders.
  • Cost: 250 BC
  • Reduction of enemy Advantage factor: -40%~-50%
  • Planet quality Drop: -10%~-30%
  • Planetary improvements Destroyed: -20%~-30%
  • Sort of a halfway point between Mass Drivers and Tidal Disruption, except it costs slightly more. No real reason to use this.

Side note: Illudium Phosdex, according to Duck Dodgers of the 24th and 1/2 century (Daffy Duck), is the secret ingredient of shaving cream. On his quest to get more, he met Marvin the Martian who in another episode attempted to blow up our planet. Whe Bugs thwarted his attempt, Marvin was quoted as saying: "Where's the Kaboom? There was supposed to be an Earth-Shattering-Kaboom." I wonder if the text and the Loony Tunes connection are more than coincidence?

Tidal DisruptersEdit

  • Description: By scattering gravity-altering satellites into orbit around inhabited planets, we'll be able to control the oceans and bury our enemy in a watery grave. Monsoons across the globe will greatly decrease enemy defenses, but will also destroy almost all planetary improvements.
  • Cost: 200 BC
  • Reduction of enemy Advantage factor: -40%~-50%
  • Planetary improvements Destroyed: -80%~-100%
  • Use this when you don't intend to keep any of the established Planetary Improvements on the planet.


  • Description: Through the miracle of advanced artificial intelligence, we are now able to send smart robots onto the battlefield. These fighters pack quite a punch, but can still be taken out with relative ease and are fairly expensive to produce. They are also slightly reckless when it comes to close quarters fighting, so some improvement loss is to be expected.
  • Cost: 500 BC
  • Bonus to Advantage factor: 40%~70%
  • Planetary improvements Destroyed: -5%~-10%
  • Use it if you have money, but not enough troops. The chance for destroying a building is lower than stated (about 2%).

Gas WarfareEdit

  • Description: Preceding attacks, viral clouds will be released upon the most populous areas of the target world. Our enemies defensive strength will be weakened, but irreversible damage to organic life on the planet will hurt overall planetary quality.
  • Cost: 200 BC
  • Reduction of enemy Advantage factor: -15%~-30%
  • Planet quality Drop: -5%~-20%

Information WarfareEdit

  • Description: Communication vessels orbiting inhabited planets will warn citizens of our invasion plans. By promising them a better life under our rule, unhappy citizens are likely to join our side. However, for proper distribution of our message, the price will be high.
  • Cost: 800 BC
  • Converted Troops: 0.2-0.4% planetary population for each percentage of unhappiness on that planet.
  • Use it when facing a planet with large population and low (below ~65%) approval. If you have significant advantage in soldiering, you may end with more pop than you've brought troops.
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