Espionage and Intelligence in Xterium — Probes and Data Accuracy

Before launching an attack, an experienced player always sends out a scout—otherwise, you might run headlong into the enemy’s defenses blindly. Let’s break down how espionage works in Xterium: what methods are used for reconnaissance, what information can be gathered, and why accuracy is key here—not just a matter of “luck or no luck.” The numbers come directly from the game’s code.

Where do these numbers come from? The probe’s specifications, the data accuracy formula, and the notification conditions are taken directly from the game engine. Tactical tips come from the community (wiki, forum). Combat mechanics are covered in the article “How Combat Works”.

Spy Probe — Inexpensive and Very Fast

Reconnaissance is carried out by a spy probe. It costs only 20 metal and 40 crystals, flies extremely fast, and uses almost no fuel. The trade-off is complete vulnerability: the probe has almost no armor or shield, it cannot attack—and in combat, it is destroyed by any single shot. But it doesn’t engage in combat during routine reconnaissance anyway.

To build probes, you need a shipyard and the initial level of espionage technology.

Intelligence always gets through—there are no failures

This is a key difference between Xterium and many similar games. The game’s code does not include a chance of reconnaissance failure, nor is the probe lost during reconnaissance. A probe sent on a reconnaissance mission always reaches its destination and always returns with a report—it does not engage in combat with the planet’s defenses.

So the question isn't "will we be able to gather intelligence?" but rather how accurate the data will be. That's the real mechanics of it.

The most important thing is data accuracy

The accuracy of the report depends on whether your espionage level is higher or lower than that of the target:

Report error = difference in spy levels × 3% − 15% (never below 0 and never above 50%). The difference is the target's level minus yours.

What does this mean:

As long as the target is no more than five spy levels above you, you see exact figures for its resources, fleet and defence: those five levels are a free allowance. Beyond that the numbers in the report drift randomly within the error margin, and attacking on such a report is risky. A repeat flight to the same planet becomes available after 15–60 seconds — the longer, the higher the target's spy level. And if the target is 30 levels above you, the reconnaissance is not sent at all.

What the report shows

In the current version of the game, reconnaissance reveals everything at once, regardless of the level difference: the planet’s resources, fleet, defenses, buildings, and bonuses. The espionage level does not affect what is visible, but rather how accurate these numbers are (see "Margin of Error" above).

Will the victim notice the reconnaissance?

A victim may receive a notification that an alien fleet has been spotted near their planet—but not always. The notification is sent only if the conditions specified in the code are met:

• The victim has logged into the game within the last 5 days (no notifications are sent to inactive users);
• This is not a repeat scan of the same planet within a couple of seconds (spam protection);
• The planet is not in the second galaxy (notifications about exploration are disabled there);
• you are not 15 or more levels above the target in spying — with such a lead no notification is sent at all;
• with a 10-level lead the target does get a notification, but sees neither the scout's name nor its planet;
• the notification arrives with a delay of 1 to 10 minutes: about five minutes at equal levels, and the stronger your spying, the later the target finds out.

In other words, by carefully scouting an inactive player, you can gather information without raising any suspicion.

How to Strengthen Intelligence

• "Espionage" technology—the main parameter: the higher its level, the more accurate your reports will be and the harder you’ll be to detect (your protection against enemy intelligence also increases).
• The Scout Senator grants additional espionage levels at high upgrade levels (for more details, see Senators).
• The "Protection Against Espionage" planetary anomaly grants the target a tiny bonus equal to its level—the effect is minimal.

How to Apply This

• Always scout before attacking—it doesn't cost much, there's nothing to lose, and you have nothing to lose.
• Keep your espionage level at least as high as that of your targets—otherwise, the data will “leak,” and the attack will turn into a gamble.
• Accurate report = safe attack: you can see the actual defenses and fleet and avoid putting your own fleet at risk. For details on how combat works, see the article “How Combat Works”].
• Exploring inactive sites rarely triggers an alarm—but the loot obtained from them depends on their reserves (see “Storage and Looting”).

Frequently Asked Questions

Is it possible to lose a spy probe while on a reconnaissance mission in Xterium? No. In the game code, reconnaissance is always successful; the probe does not engage in combat and is not destroyed during a normal reconnaissance mission.

What determines the accuracy of intelligence data? On the difference in spy levels: error = difference × 3% − 15%, capped at 50%. As long as the target is no more than five levels above you, the data is exact.

What do the intelligence reports show? Everything at once: resources, fleet, defenses, buildings, and bonuses. The difference in levels only affects the accuracy of the numbers, not what you see.

Does the victim always find out about the surveillance? No. You'll only receive a notification if the victim has logged in within the last 5 days, the scouting isn't repeated within seconds, and the planet isn't in a different galaxy.

What to Read Next

• How the "" fight works
• Warehouses and Looting
• Fleet speed, flight time, and deuterium consumption in Xterium Fleet Speed and Fuel Consumption]
• Ships and Senators