UFO Incursions (Apocalypse)
This page lists the types of UFO incursions, the craft involved on each alien mission and their specific roles.
Each incursion fleet will consist of 1-7 craft, each with a specific composition and role than can be consulted on the tables below. Each force will consist of UFOs with a primary mission which can be Infiltration, Subversion, Attack and Overspawn Drop. Usually there will also be additional craft flying as escorts and in a few cases an Infiltration or Overspawn Drop force will also have craft assigned to Attack hostile buildings.
The composition of the fleets depends on the UFOs available at the Alien Dimension. Thus, certain fleets will only appear after a certain date. The fleets are sorted in order of priority; for a given mission, the aliens will always use the highest-numbered fleet (furthest down on the list) that they can.
The game seems to choose the mission randomly from a list of 10 missions that at game start will consist of only Infiltration ones. As the weeks go this list is changed and other missions are added to that list, although the probability of them occuring will initially be 1 in 10.
*These fleets will never appear, as the ships required will also fulfil a higher-priority fleet.
**This fleet can appear as long as the aliens have at least one Battleship and one Escort Ship (though two Battleships will still appear in Mega-Primus). This is the result of a bug in the spawn routine; instead of checking whether there are two Battleships, it checks whether there is one Battleship twice.
- Subversion fleets can appear from Week 5 onwards.
- Attack fleets appear from Week 4 onwards.
- Overspawn drops can appear from Week 8 onwards.
- A fleet with two Motherships is guaranteed to be on an Overspawn Drop mission.