Debris, the Moon and Its Destruction in Xterium — How It Forms and How to Destroy It

After a major battle, a field of debris remains above the planet, and sometimes a moon appears. These two events are directly related. Let’s take a look at how many resources go into the debris and what determines the chance of a moon appearing—all based on the game’s code.

Where do these numbers come from? The shard percentages and the moon chance formula are taken directly from the game’s combat engine settings. Explanations and tips come from the community (wiki, forum). The combat mechanics are covered in the article “How Combat Works”.

How much ends up in the rubble?

When ships and defenses are destroyed in battle, part of their value remains above the planet as debris:

• Fleet → 50%. Half of the resources (metal and crystal) from destroyed ships are converted into a debris field.
• Defense → 0%. Destroyed defense units do not break into pieces at all.

This is an important distinction. You cannot bomb an enemy’s defenses “to smithereens”—only a destroyed fleet (whether your own or the enemy’s) leaves behind debris.

Who Collects the Debris?

A special ship—a recycler—collects the debris field (its hold capacity determines how much can be hauled away at a time). Debris is available to both sides: after a battle, anyone can fly in to collect it, not just the winner. That’s why a large debris field is a prize that sometimes prompts a separate race.

Moon Chance: 1% per 1,000 shards, up to 20%

The moon may form from a field of debris immediately after the battle. The formula from the engine is simple:

• Every 1,000 shards grant a +1% chance of a moon.
• The maximum is 20%.

In other words, to achieve the maximum 20% chance, you need a field containing approximately 20,000 fragments (metal and crystal combined). Adding more fragments won't increase the chance any further—the cap is 20%.

After the battle, the game “rolls the die” once: if the result falls within the probability range, the moon appears. If not, there will be no moon, no matter how many shards are lying around. This is a one-time check; it does not accumulate.

Examples

Why Do We Need the Moon?

The Moon is a separate object near the planet where special structures are built (for example, for long-range reconnaissance and fleet teleportation). It’s difficult to obtain a moon due to the 20% cap, so large fleets are deliberately sent into battle specifically to create a large debris field.

How to Apply This

• If you want the moon, you'll need a major battle with heavy fleet losses (either your own or the enemy's): only the fleet drops debris, and you'll need to collect ~20,000 to reach a maximum of 20%.
• If you don't want to give your enemy scraps and a shot at the moon—don't lose a large fleet in enemy airspace. The best defense is [](/knowledge/guides/kak-ne-poteryat-flot) fleet save.
• Defense is safer than the navy in this regard: even if it is destroyed, it leaves no debris behind.

How to Destroy an Enemy Moon

A moon can be not only obtained but also destroyed. This requires a special ship — the Death Star — and a dedicated "Destroy Moon" mission. In game version 2.12.7 the destruction mechanic was reworked; here is how it works, based on the game code.

What Determines Success

The chance to destroy a moon is calculated by the engine's formula and depends on several things at once:

• The moon's diameter. The larger the moon, the lower the chance to destroy it. The biggest moons (diameter 10,000 and above) get their chance additionally divided by 1.5 — they are especially hard to break.
• The number of Death Stars in the mission — the more, the higher the chance.
• The Particle Accelerator on the moon. Each level of the Particle Accelerator raises the moon's protection against destruction. A well-leveled Accelerator is the best insurance against a wipe.
• Alliance and senator bonuses (protection against moon destruction) also lower the attacker's chance.

What changed in 2.12.7. The Death Stars' destructive power in the formula was reduced — destroying large, well-protected moons became noticeably harder than before.

Two Outcomes on Success

If the roll succeeds, what happens next depends on the moon's size:

• A small moon (diameter roughly up to 6,000) is destroyed completely. The moon disappears entirely, along with all of its buildings.
• A large moon (diameter 6,000 and above) cannot be wiped in a single strike, so it is temporarily disabled: it goes offline for a while (from 12 hours for the largest moons to about two days for borderline ones), loses part of its diameter and fields, and its buildings may lose levels.

What Happens to Buildings and Debris

During the partial destruction of a large moon:

• Each moon building, with a chance of 1% to 50% (higher the closer the moon is to the threshold), loses one level. The exceptions are the Particle Accelerator and the Alliance Depot — these are never destroyed.
• 30% of the demolished building level's cost goes into the debris field above the moon.
• An additional 20% of the cost of the moon's last expansion level (metal and crystal) also falls into debris.
• Star ore: part of the last expansion level's star ore (randomly — from 1 unit up to 20% of that level) goes straight into the attacker's fleet hold.

The Risk for the Attacker

Destroying a moon is a risky business. The Death Star fleet may perish in the explosion of the moon being destroyed. The chance of losing your own fleet equals the square root of the diameter divided by 2 (as a percentage): for a moon with a diameter of 10,000 that is about 50%. The larger the moon, the higher the odds you lose your Death Stars along with it.

Frequently Asked Questions

What is the maximum moon chance in Xterium? 20%. That's the cap—the chance won't go any higher, no matter how many shards there are. To reach the maximum, you'll need a field with about 20,000 shards.

How is the moon's probability calculated? 1% for every 1,000 shards (metal + crystal combined), but no more than 20%. After a battle, the game checks the chance once—this is a one-time check, not cumulative.

Does the defense drop debris? No. Destroyed defenses do not leave any debris (0%). Debris is only dropped by a destroyed fleet—50% of its value.

Who can pick up the pieces? Any player who arrives at a field as a processor isn't just the winner of the battle. A large field often serves as a separate prize.

How do you destroy an enemy moon? You need a Death Star ship and the "Destroy Moon" mission. The chance of success is lower the larger the moon and the higher the level of the Particle Accelerator on it. Small moons are destroyed completely; large ones are only temporarily disabled, losing diameter and building levels.

Can you protect your own moon from destruction? Yes. The main defense is the Particle Accelerator: each of its levels lowers the enemy's chance to destroy your moon. Alliance and senator bonuses against moon destruction also help. The Particle Accelerator and the Alliance Depot never lose levels during partial destruction.

Is it dangerous to destroy a moon yourself? Yes. The Death Star fleet may perish in the explosion. The chance of losing your own fleet grows with the moon's diameter — for the largest moons it is about 50%.

What to Read Next

• How the "" fight works
• How Not to Lose the Fleet
• Ships and Battle