How a battle plays out
A battle in Xterium is resolved automatically, round by round. The attacking fleet and the defender's fleet and defence exchange fire; everything is decided by the ratio of damage, shields and armour on both sides.
Damage and shots
Targets are chosen at random, but almost entirely in proportion to the target's shields (≈99% by shields, ≈1% by ship count). Damage first drains the shield, then hits the armour.
A shield absorbs a lot of small hits (roughly "a million cells" per ship). Between rounds the shield partly regenerates (each ship has its own percentage).
Rapidfire gives an extra damage multiplier of ×1.5 against targets a ship is especially effective against. Rapidfire does not work against resource transports.
The "rock-paper-scissors" rule applies. By class: light beats heavy, heavy — medium, medium — light. By type: destroyer beats cruiser, cruiser — battleship, battleship — destroyer. The ram is effective against defence. Damage is higher against a "favourable" target (multiplier ×2 … ×5), weaker against an unfavourable one (×0.5). Detailed tables — in the Ships and Defence sections.
How much harder a favourable target is hit
Effectiveness by class and type is a specific damage multiplier. The exact ladder (from an unfavourable target to a perfect one):
On top of this multiplier, "favourable" targets also get rapidfire ×1.5 with extra shots. That is why a smart fleet composition against a specific enemy decides the battle outcome more than sheer fleet size. Full "who beats whom" tables — in the Ships and Defence sections.
When a ship explodes
A ship does not necessarily die the moment its armour runs out. The more the armour has dropped relative to full, the higher the chance it explodes in this round (the chance starts to grow at roughly 5% damage). That is why heavily damaged ships are often finished off, while lightly grazed ones survive and repair between rounds.
After the battle: restoration and debris
A lost fleet does not come back — its remains turn into debris (half of the cost), which recyclers collect. Defence partly rebuilds itself after the battle and does not turn into debris. After large battles a moon may form over the planet (the more debris there is, the likelier it is).
Weapon points
"Weapon points" are a measure of a player's combat power. They come not only from ships: the total also includes buildings, combat research, defence and arsenal upgrades. The overall figure is used in the ratings and in rewards for contracts and missions.
| Class | Points per 1 ship | |
|---|---|---|
| Light Ships | 0.1 | Fighters, cruisers, and light-class (FL) destroyers |
| Medium-sized ships | 0.5 | Mid-class ships (FM) |
| Heavy ships | 5 | Heavy-class ships (FH) |
| Prime Fleet | 0.5 – 25 | Premium Ships: The More Powerful They Are, the Higher the Contribution (0.5 / 2.5 / 25) |
| Transport / Probe | 0.04 / 0.005 | Support Vessels |
Weapon points from the fleet = the sum of (class multiplier × number of ships). For example, 100 heavy ships = 100 × 5 = 500 weapon points. Besides the fleet, points also come from buildings, combat research, defence (counted only on the largest planet) and arsenal upgrades — so the threshold can be reached without a big fleet.
Newbie protection. While a player has fewer than 500 000 weapon points, they are protected — strong players cannot attack them. Past that threshold the protection is lifted.
Strong versus weak, and war points
Combat is limited by the "strong versus weak" rule, and during alliance wars destroying an enemy earns special war points.
If a target has less than a third of your weapon points (and is itself below the threshold), that target is protected and cannot be attacked. You also cannot ship resources to a player who is twice as strong as you in points.
Attacking a much stronger opponent is allowed, but it is flagged: the reward for it is calculated from the size ratio of the two sides.
During an alliance war, war points for an enemy fleet destroyed are doubled (×2 versus ×1 in peacetime), and for defence — ×0.5 versus ×0.25. A victory in battle gives ×0.75 to the total, a draw or retreat — ×0.5.
War points scale with the ratio of the two sides' points: hit someone weaker than you and you earn fewer. War points accumulate for you and your alliance and determine your standing in the alliance tournament and the alliance war.
Best-counter calculator
Mark one or more enemy units (ships or defence) — we show which of your units are on average the most effective against the whole selection, by the in-game efficiency multiplier. On top of it, favourable targets also get the ×1.5 rapidfire.
Multipliers are verified (combat effectiveness of ship vs ship and ship vs defence). Full "who beats whom" tables are on the Ships and Defence pages.
