AI planets can be alerted.
An AI planet is alerted when it is adjacent to a neutral or Human planet, when it has hostile military forces on it (not necessarily Human), when an adjacent planet has hostile military forces on it.
Alerted planets are displayed with a red glow on the galactic map (instead of a white glow). An alerted planet is more likely to receive Reinforcement.
When planning galactic conquest, players should take into account the number of planets they would alert. Planets with a high Mark would be reinforced with high Mark ships. The less alerted planets there is, the more concentrated the Reinforcements will be.
It's often a good strategy to alert many low-mark planets in order to keep the AI reinforcements scattered.
|Here, the Human territory (purple) have a single wormhole link leading to AI territory, which is easier to defend, but puts a single, MkIV planet on alert, which is likely to receive a lot of MkIV reinforcement.|
|After taking that MkIV planet, the Human territory has three wormholes to defend, but puts three planets on alert, the most powerful being MkIII, which will disperse AI reinforcements. That new planet will be harder to defend, but it can be a buffer, letting attacks pass through, toward the planet behind which has only one wormhole to heavily fortify.|