Alien Leader Chances (LWR)
Chance for an Alien Leader
The percent chance for an Alien Leader to appear in each pod is:
3/4/5/6/7 [for Easy/Classic/Brutal/Impossible/Pain] x (Alien Level + 5)
Alien Leader Chance is multiplied by one tenth of the Alien Level for the following Aliens: Cyberdiscs, Mechtoids, Sectoid Commanders, Sectopods, Ethereals. This is capped at AL10 giving them a 1x multiplier and thus making them have the same spawn rate as other leaders.
Alien Leader Chance is reduced by half if the Alien Level is equal to 2.
Alien Leader Chance is set to 0% if the alien level is the first level this alien appears.
Alien Leader Chance is set to 100% on the following missions: Terror Sites, Alien Base Assaults, the Exalt Base Raid, and the Temple Ship Assault, regardless of alien level.
Multiple Alien Leaders:
At Alien Level 6 and later there is a small chance for any followers in a pod to be upgraded into a leader. This percent chance per follower unit is:
(Alien Level - 5) x 0/1/2/3/4 [for Easy/Classic/Brutal/Impossible/Pain]
This chance is set to 0% if the alien level is the first level this alien appears unless the mission is a Terror Site, Alien Base Assault, the Exalt Base Raid, or the Temple Ship Assault.
Half of the time these extra leaders will be leader level 1, and the other half of the time they will use the normal leader level formula but with the final level halved.
Additionally, all Medium and larger UFOs have their own extra chance for non-leaders to become level 1 leaders. This chance is 20%/40%/60% for Medium/Large/Very Large UFOs respectively.
Alien Leader Level
The formula to determine Leader Level is:
Leader Level = (Alien Level + Rand(Alien Level))/2 + Modifiers
Difficulty Modifier:
- Easy: -2 leader levels
- Classic: -1 leader levels
- Brutal: 0 leader levels
- Impossible: +1 leader levels
- Pain: +2 leader levels
UFO Size Modifier:
- Medium: +1 leader level
- Large: +2 leader levels
- Extra Large: +3 leader levels
Terror Site Modifier:
- +1 leader levels
Council Mission Modifier:
- leader levels halved
Exalt Base and Temple Ship Assault
- Automatic leader level 8
Bonus Leader Levels and Alien Level cannot make the Leader Level go higher than 8.
Champion (Level 9) Alien Leaders
After determining leader level, if the level is 8, there is a 20% chance to be promoted to level 9 (max), which will produce a champion. This chance is increased to 30%/40%/50% on Medium/Large/Very Large UFOs. This can only occur every 13/9/6/4/3 leaders (based on difficulty).
The Exalt Base Assault will have preset Champion Alien Leaders. The Temple Ship Assault will have 2 guaranteed Champions (the Uber and Atlas) and other aliens will have their chance of promoting to champion increased to 100% (but still be capped in how often they can be promoted).
Features of Alien Leaders
Aliens leaders have purple HP and are identified in the HUD by taller alien head. Champion aliens (level 9 leaders) have gold HP. Both types of leaders usually have a plethora of bonus stats and perks, on top of guaranteed perks: Sprinter for all leaders, and Plasma Shield for all champions.
Any turn this unit takes more than 30% of its max HP in damage it gains a shield of pure plasma. The shield is separate from the unit, cannot be crit, and can absorb 20/40/60/80/100 damage until the end of the current turn. An active shield staunches bleeding and makes this unit act as if it has not been damaged this turn -- this can disable or re-enable other abilities. This unit cannot be pinned.
Killing or capturing an alien leader provides the squad with additional xp.