UFO Incursions (Apocalypse)
Alien Craft Quantity and Mission Styles appearing in Mega-Primus
UFO Incursions
Aliens send their craft through a 'portal', called a Dimension Gate, appearing at random locations and at random times within the cityscape as time progresses. It is an invunerable device.
UFO Quantity Maximums
UFOs are 'grown' in the Alien Dimension at the start of the week and of only a certain quantity and type dependant on the number of weeks elapsed in the game:
| Week |  |
 |
 |
 |
 |
 |
 |
 |
 |
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|---|---|---|---|---|---|---|---|---|---|---|
| 1 | 9 | 9 | ||||||||
| 2 | 2 | 4 | 3 | 2 | ||||||
| 3 | 2 | 4 | 2 | 2 | 3 | |||||
| 4 | 1 | 2 | 1 | 1 | 2 | 2 | ||||
| 5 | 1 | 1 | 1 | 1 | 2 | |||||
| 6 | 1 | 1 | 1 | 1 | 1 | |||||
| 7 | 1 | 1 | 1 | 1 | 1 | |||||
| 8 | 1 | 1 | 1 | 1 | 1 | |||||
| 9 | 1 | 1 | ||||||||
| 10 | 1 | 1 | ||||||||
| 11 | 1 | 1 | 1 | 1 | ||||||
| 12 | 1 | 1 | ||||||||
| 13 | 1 | 1 | 1 | |||||||
| 14 | 1 | 1 | ||||||||
| 15 | 1 | |||||||||
| 16+ | 1 | 1 | 1 | 1 | ||||||
| Maximum | 15 | 15 | 6 | 6 | 6 | 6 | 6 | 6 | 4 | 2 |
Alien Missions
Aliens will perform certain actions within Mega-Primus using a variety of UFO craft types and quantity. Other UFOs will escort specific UFOs on missions such as:
- Infiltration
- Search
- Bombing
- Terror
Mission Schedules
At the start of each week (Monday), the aliens will develop a time-table of randomly chosen days and times within this new week. When the time-tabled slot becomes current, a style of mission will be randomly chosen dependant on importance (the percentage chance) and the number of weeks elasped in the game:
| Week | Infiltration | Search | Bombing | Overspawn Drop |
|---|---|---|---|---|
| 1-3 | 100% | 0% | 0% | 0% |
| 4 | 90% | 0% | 10% | 0% |
| 5-6 | 80% | 10% | 10% | 0% |
| 7 | 70% | 10% | 10% | 10%* |
| 8 | 50% | 20% | 10% | 20% |
| 9-11 | 40% | 20% | 20% | 20% |
| 12 | 30% | 30% | 20% | 20% |
| 13 | 30% | 20% | 30% | 20% |
| 14 | 40% | 20% | 20% | 20% |
| 15-18 | 30% | 20% | 20% | 30% |
| 19 | 20% | 20% | 30% | 30% |
| 20+ | 10% | 40% | 20% | 30% |
Once a mission is selected, the aliens will allocate the UFOs required (if available) in the Alien Dimension to immediately spawn into Mega-Primus.
Note: An Overspawn Drop for Week 7 is an error in the game since the craft needed, a Mothership, is not yet available.
The alien craft will materialise from the dimension gates in sequence (all Primary craft, all Escort craft, all others) according to their selected mission. When the first craft has spawned in, the next craft due will choose a gate randomly of the three, until all are present. (A save/load between each spawn will again randomise the gate choice for the UFO due to appear next.)
The alien crafts listed in "Escort" are assigned protection duty of the "Primary" group's leader, hence, the first craft that spawned into the city is (always) the leader of all primary craft. If the leader is lost when under escort, the assigned escorts will select the 'second in command' primary craft as the new leader... until all primaries are either shot down or have escaped. If no more (viable) primary craft are present, any escorts remaining will also return to the gates. Escorts are assigned escort duty only and will not escort other designated escorts. Primary UFOs will proceed with their mission regardless if an escort is available.
Craft Selection
Any alien mission chosen in the schedule will only commence if the required UFOs are present in the Alien Dimension, that is, the mission will only start if the needed craft are available, and if not, the mission will not start and the 'time and day' mission slot is forfeited.
- eg: It is week five and a time-tabled mission slot is currently available. The game will now randomly chose a style of mission: ...infiltration! Since it is week five, the scheduled infiltration mission is 13, which needs 2xassault + 2xbombers. In the alien dimension, a large selection of only the earlier UFOs are present. There are no bombers! The infiltration selection will now move 'upwards' until the mix of UFOs present in their homeworld suits the group requirement. It has found 1xtransporter and 3xscouts. The infiltration UFO group is now valid (Mission 9/Week 3): 1xassault + 1xtransporter + 3xscouts. These UFOs will now start to spawn into Mega-Primus. If a group cannot be formed, the mission will not proceed.
UFOs in the Bombing column will attack any hostile organisation's buildings.
Mission: Alien Infiltration
Alien crafts used to drop/insert/infest alien lifeforms into buildings:
| Mission | Primary | Escort | Bombing | Week |
|---|---|---|---|---|
| 1 |  |  | 1 | |
| 2 | | | 1 | |
| 3 |  | 2 | ||
| 4 | |  | 2 | |
| 5 | | | 2 | |
| 6 |  | | 4 | |
| 7 |  | | 3 | |
| 8* | | 4 | ||
| 9 | | | 3 | |
| 10 | | | 3 | |
| 11 | | 4 | ||
| 12 | | | 4 | |
| 13 | |  | 5 | |
| 14 | |  | 8 | |
| 15 | | | | 8 |
| 16* |  | | 7 | |
| 17** | | | | 7 |
| 18 | | | 7 | |
| 19 |  | 8 | ||
| 20 | | | 8 |
*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 an error in the allocation of available crafts - instead of checking whether there are two Battleships, it checks whether there is one Battleship twice.
Note: An infiltration attempt into an undetected and unknown X-Com Base will proceed with a Base Defence mission.
Mission: Alien Search
When an Alien Search mission becomes a valid time-tabled mission, UFOs spawn into Mega-Primus and randomly select a building and will 'drop blue rain' over a particular part of the building, but within the property outline. They do not target the home-cell as expected. Multiple UFOs can 'drop rain' on the same building in the same mission one after the other. It seems the Aliens do not remember which building has been searched. There is a an error with this routine.
Caution: Blue Rain = Searching.
Alien crafts used to search a building for an X-Com base:
| Mission | Primary | Escort | Week |
|---|---|---|---|
| 1 | | 5 | |
| 2 | | 5 | |
| 3 | | 5 | |
| 4 | | 5 | |
| 5 | | 5 | |
| 6 | | 5 | |
| 7 | | 5 | |
| 8 | | 5 | |
| 9 | | | 7 |
| 10 | | | 8 |
- X-Com-Base Attacks will commence at the start of Week 5.
- An Alien Search mission style will always be possible. It does not cease if an X-Com Base has been found.
Mission: Bombing Buildings
Alien craft groups assigned for Mega-Primus building destruction, using gun and bombs, of hostile organisations in Mega-Primus.
| Mission | Primary | Escort | Week |
|---|---|---|---|
| 1 | | 4 | |
| 2 | | | 4 |
| 3 | | 5 | |
| 4 | | | 4 |
| 5 | | | 5 |
| 6 | | 6 | |
| 7 | | | 7 |
| 8 | | 9 | |
| 9 | | 9 | |
| 10 | | 8 |
- Building Bombing will commence at the start of Week 4.
Mission: Overspawn Terror
A terror misssion style which always contains a Mothership as the primary leader to randomly 'unload' an Overspawn terror unit into Mega-Primus. Escort assigned craft may also attack buildings at random as with the craft listed in the Bombing column.
| Mission | Primary | Escort | Bombing | Week |
|---|---|---|---|---|
| 1 | | 8 | ||
| 2 | | | 8 | |
| 3 | | | | 8 |
| 4 | | | 8 | |
| 5 | | | 11 |
- Overspawn Terror will commence at the start of Week 8.
- A fleet with two primary Motherships is certain to be an Overspawn Terror mission.
Apocalypse Mission
A special version of a Bombing mission which only happens once, once the Control Chamber in the alien dimension is destroyed. The next alien mission that is time-tabled wiil always be Apocalypse Mission.