Planetary Defense Guide

Planetary defense structures are the passive guardians of your empire. Unlike fleet ships, they never fly away and leave you exposed — they sit on your planet and fight every incoming attack automatically. A well-defended planet deters most raiders before an attack is even launched, because experienced players scout first and skip planets where the math doesn't favor them.

Why defense matters

The single biggest vulnerability for new players is zero or minimal defense on a resource-rich planet. A large undefended stockpile is the most attractive possible raid target. Defense structures don't just protect you when attacked — they prevent most attacks from happening at all by making your planet look expensive to crack.

All 10 defense structures

Rocket Launcher

• Weapon: 80 | Shield: 20 | Armour: 2,000
• The cheapest defense structure. Build large numbers early.
• Cost: very low (Metal + Crystal)
• When to build: immediately. Your first 50–100 Rocket Launchers are your first line of defense.

Light Laser

• Weapon: 100 | Shield: 25 | Armour: 2,000
• Marginally stronger than Rocket Launchers. Good filler between heavier structures.
• Requires: Laser Technology 1, Energy Technology 1
• When to build: early-mid game as a cheap supplement to Rocket Launchers

Heavy Laser

• Weapon: 250 | Shield: 100 | Armour: 8,000
• Significant upgrade in armor. Can absorb several hits before going down.
• Requires: Laser Technology 3, Energy Technology 3
• When to build: mid-game, mixed with Rocket Launchers

Gauss Cannon

• Weapon: 1,100 | Shield: 200 | Armour: 35,000
• High weapon value relative to cost. Excellent damage per resource.
• Requires: Weapons Technology 3, Shielding Technology 1, Energy Technology 6
• When to build: mid-game. One of the most cost-effective defense purchases.

Ion Cannon

• Weapon: 150 | Shield: 500 | Armour: 8,000
• Very high shields. Exceptional against shield-breaking attacks.
• Requires: Ion Technology 4
• When to build: mid-game on planets you expect to be attacked repeatedly

Plasma Turret

• Weapon: 3,000 | Shield: 300 | Armour: 100,000
• The most powerful standard defense structure. Massive armour and weapon damage.
• Requires: Plasma Technology 7
• When to build: late-game. Expensive to research and build but an enormous deterrent.
• Plasma Technology level also boosts Plasma Turret damage — research pays off here.

Small Shield Dome

• Weapon: 1 | Shield: 2,000 | Armour: 20,000
• Provides a global shield bonus to all defense structures on the planet.
• Only one can be built per planet.
• When to build: as soon as you can afford it. The global shield bonus amplifies every other defense.

Large Shield Dome

• Weapon: 1 | Shield: 10,000 | Armour: 100,000
• Stronger version. Replaces the Small Shield Dome benefit.
• Only one per planet.
• Requires: Shielding Technology 6
• When to build: late-game flagship defense investment.

Anti-Ballistic Missile (ABM)

• Stored in the Missile Silo. Intercepts incoming Interplanetary Missiles.
• Each ABM destroys one incoming IPM before it reaches your defense.
• When to build: when you know you're in a war and enemies have Missile Silos.

Interplanetary Missile (IPM)

• Stored in the Missile Silo. Launched at enemy defense structures.
• Destroys one random defense structure per missile at the target.
• When to use: before a major fleet attack to soften enemy defenses. IPMs don't trigger a battle — they hit silently before your fleet arrives.

Recommended defense build order

Phase 1 (early game): 50–100 Rocket Launchers. Cheap, available immediately, good enough to deter small fleet raids.

Phase 2 (mid-game): Add Gauss Cannons (high damage per cost), Heavy Lasers (armor buffer), Ion Cannons (shield value). Build a Small Shield Dome as soon as prerequisites are met.

Phase 3 (late-game): Plasma Turrets backed by a Large Shield Dome. A planet with 30 Plasma Turrets + a Large Shield Dome + 200 Rocket Launchers is one of the most difficult targets in the game to attack profitably.

Defense vs fleet composition

Different attackers bring different fleets, and your defense should account for this:

• Light Fighter swarms: Rocket Launchers and Heavy Lasers handle these well through volume
• Cruiser fleets: Gauss Cannons + Ion Cannons are effective
• Bomber attacks: Bombers have rapid fire against all defense. Counter with sheer quantity and Shield Domes — there's no perfect counter to a large Bomber fleet except not being a target worth bombing
• Deathstar: a single Deathstar vaporizes most planetary defense. At this level, fleet-saving (see Fleet Saving Guide) matters more than building more defense

Key principle: quantity matters

Defense structures are destroyed when their hull reaches zero and are not rebuilt automatically after battle. A planet with 10 Plasma Turrets sounds impressive but can be cracked by a single focused attack. A planet with 500 Rocket Launchers + 50 Gauss Cannons + 20 Ion Cannons + 10 Plasma Turrets forces any attacker to bring overwhelming force and accept significant losses. The deterrence value of large defense numbers is as important as the combat value.

For missile combat details, see the Facilities Guide (Missile Silo section).