Psionic (Long War)

Psi powers have been significantly overhauled in Long War. Psi talent is now trained, not discovered, so with enough time and attempts, every soldier can be a psionic (barring some exceptions). There are many more powers distributed among more levels.

Class icons

Assault	Infantry	Gunner	Rocketeer	Scout	Sniper	Medic	Engineer

Psi-abilities

Level	Rank	Psionic Ability
1	Awakened	Regen Biofield Nearby allies are healed for 1 health each turn, and has a 100% chance to remove acid effects (after b15f2). This does not repair damage to body armor or other hp-granting items. Imposes +24 hours postmission fatigue for psi soldiers. (Passive ability)	Neural Feedback Causes damage to psi attackers and puts all of their psi attacks on cooldown. Does not reduce the attacks' chance of success. Protects the psion and nearby allies who pass a will check. Imposes +24 hours fatigue after missions.	Mindfray Causes the target to lose grip on reality, causing -25 aim/stack, -25 will/stack, a reduced area-of-effect attack range, reduced mobility, and doing one base damage. Robotic units are immune. Lasts 3 turns. 2 turn cooldown. Imposes +24 hours fatigue after missions.
2	Sensitive	Distortion Field Nearby allies in cover receive +10 Defense. Imposes +6 hours postmission fatigue for psi soldiers. (Passive ability)		Psi Inspiration Removes Mindfray and panic from all allies within 3 tiles, and strengthen their Will by +30 for 3 turns, 4 turn cooldown. Imposes +6 hours fatigue after missions.
3	Talent	Psi Panic Cause target to panic on its following turn, if the target's Will is overcome. The duration is (caster Will / 50) turns; fractional results have a chance to be rounded up, the chance is proportional to the distance to the next integer. Robotic enemies are immune, 2 turn cooldown. Imposes +6 hours fatigue after missions.		Mind Merge Merge minds with the target, granting the target +25% critical chance, bonus will, and temporary health (for aliens) or damage reduction (for humans: DR=caster_will/60). Imposes +6 hours postmission fatigue for psi soldiers.
4	Adept	Psychokinetic Strike Project a bolt of pure psi force that destroys cover but does not harm units. 4 turn cooldown. Imposes 12 hours additional post-mission fatigue.	Pyrokinesis Ignite fires at the target location. Does not cause injuries. Imposes +12 hours postmission fatigue for psi soldiers.	Telekinetic Field Create an immobile telekinetic field that lasts through the enemy turn. The field distorts and deflects incoming attacks, granting +40 Defense to allies within the field, 4 turn cooldown. Imposes +12 hours fatigue after missions.
5	Psion		Mind Control Difficult psi technique that, if successful, grants control of the target for 3 turns. Does not work on robotic enemies. 5 turn cooldown. Imposes +12 hours fatigue after missions.
6	Master		Rift Devastate an area with a storm of psi energy. The rift does more damage against targets with low Will, and reduced damage against targets with high Will. 4 turn cooldown. Requires special armor designed for psionic beings. Imposes +12 hours fatigue after missions.

Training

Limitations

MEC Troopers, Officers, and soldiers with the Neural Damping gene mod are unable to undergo psi training. Psionic soldiers cannot get Neural Damping and cannot become officers or MEC troopers.

Unlocking Psi powers

By default, only Mindfray and Neural Feedback are available. Unlocking further powers is accomplished by performing autopsies and interrogations. One exception is Rift, which requires an in-battle accomplishment.

Psi-powers are more effective based on the will score of the caster. For instance, Mind Merge will add (will/60) damage reduction to the target.

Psionic soldiers also gain 1-6 extra will per psi level (1 + rand(6)).

Psi XP

After Xenopsionics is researched, soldiers will begin accruing Psi XP by going on missions. Reaching a threshold of Psi XP requires to undergo additional Psi Training ('extra' Psi XP will not roll over for the next level). Every round of training takes approximately 5-10 days (this is halved with Nigeria's Old Path starting bonus), and its length and success chance is affected by the soldier's Will score. You can see the current Psi XP level and cap in their Barracks profile.

Psi Ranks and XP gain

In Long War Psi XP is awarded passively only after a successful mission. Thus, the more missions a soldiers completes, the faster they will unveil the mystery behind their psionic powers. Each Psi ability from the same Psi Rank provides the same passive gain. The experience gain is cumulative across all abilities learned. A soldier gains a new Psi Rank for 5 completed missions, unless the Neuroregulator (an EXALT loot item) is used. Thus, to achieve the final rank of Master it should require approximately 30 missions per soldier.

Success rate

The success rate of the training depends on the soldier's will and the level. If the target will for the level is equal to the soldier's will, the chance is 45% (65% with Mexico's starting bonus Legacy of Uxmal). It increases asymptotically to 100% at infinite will and drops to 0% at 0 will.

The target will values are:

Level 1 Awakened: 50
Level 2 Sensitive: 60
Level 3 Talent: 70
Level 4 Adept: 80
Level 5 Psion: 95
Level 6 Master: 120

Effects on Fatigue

A psi-trained soldier takes longer to recover from post-battle fatigue. The increase is dependent upon powers learned as follows:

Level 1 Awakened: +24 hours
Level 2 Sensitive: +30 hours
Level 3 Talent: +36 hours
Level 4 Adept: +48 hours
Level 5 Psion: +60 hours
Level 6 Master: +72 hours

Note the Egypt's starting bonus Gift of Osiris halves this additional fatigue.

In-game application of powers

Range

The range of Psi Inspire, Psychokinetic Strike, and Pyrokinesis scales with the users Will according to the following formula: Visual Range * (1 - (28 / (28 + Will))); this produces a max range of 1/2 of visual range at 28 Will, 2/3 of visual range at 56 Will, 3/4 of visual range at 84 Will, 4/5 of visual range at 112 Will, and so on.

The protection radius of Neural Feedback is 8 tiles away from the Psion with Neural Feedback. The protection radius of Distortion Field is 4 tiles. The healing radius of Regen Biofield is 3 tiles. The range of Mindfray, Mind Control, Mind Merge, and Rift is visual range.

Opposed Will Check

Mindfray, Psi Panic, and Mind Control require the caster and target to make an opposed Will roll. The chance of success is [CasterWill - TargetWill + BaseAbilityChance]/100. The base ability success chance for Mindfray is +50 (meaning at equal will, the ability has a 50/100 or 50% success rate). The base ability chance for Psi Panic is +35 (meaning at equal will, the ability has a 35/100 or 35% success rate. Mind Control is +15 (equal Will provides a +15% success rate).

Detailed Information

Level	Psionic Ability	Prerequisite	Description
1	Mindfray	None	The caster makes an opposed Will roll with the target at a +50 bonus. If successful, deals 1 damage to the target (increased to 2 by Shredder) and applies a 'Hallucinations' status effect that applies the following penalties: -25 Aim and Will per application of Mindfray, as well as -40% mobility and -25% AoE range.
	Neural Feedback	None	Causes damage to the psi attacker equal to the difference between the attacker and targets Will (the formula is [casterWill * 1.30 - targetWill] / 10) and puts all their psi attacks on cool down. To activate, the psionic must pass an opposed Will check with the attacker. Is always on and provides protection to allies within 8 tiles of the psionic with Neural Feedback, however the damage scales with the Will of the target and not the Psionic.
	Regen Biofield	Thin Man Interrogation	Provides +1 HP regeneration and cures acid to all ally units within 3 tiles of the Psionic soldier. The healing triggers only if an ally is wounded beyond bonus armor HP. Furthermore, the healing effect can Stabilize wounded allies without requiring the expenditure of a medkit.
2	Psi Inspiration	Sectoid Interrogation	Psi Inspiration removes all harmful mental effects (panic, hallucination, fallen comrades penalty) from everyone inside the AOE as well as grants +30 Will for the next 4 turns. Unlike in vanilla, Psi Inspiration is not centered around the user but can instead can be targeted much like a rocket. The cast distance scales with the users Will (see above).
2	Distortion Field	Muton Interrogation	Works the same as the vanilla MEC ability, that is, provides +10 defense to all units within 4 tiles of the Psionic soldier, excluding the Psionic soldier.
3	Mind Merge	Sectoid Commander Autopsy	Merge minds with the target, granting the target temporarily increased health for aliens and damage reduction for XCOM operatives based on user's Will (the HP/DR is equal to Will/50). It also grants +25% critical hit chance and a will bonus, which also scales with the mind merge caster's will (the formula is 25 + [casterWill / 10]). Mind merge can't be applied to "psionically active targets", which includes soldiers with the Psi Inspiration buff, Psions with Mind Control or Psi Panic on cooldown, those who are already mind merged, or those whose will is being buffed by a nearby officer who is Psi Inspired.
3	Psi Panic	Berserker Interrogation	Cause target to panic, if the target's opposed Will roll (at a +35 penalty) fails. Robotic enemies are immune with the exception of the Mechtoids. The duration of the panic effect is 1 + (casterWill / 50) turns, with fractional results having a chance to round up or round down as with DR. 2 turn cooldown. Note that panic has been changed a little in Long War so units will either hunker down or run, and never go berserk and shoot.
4	Psychokinetic Strike	Sectoid Commander Interrogation	A cover-destroying, free-aimed psionic attack. AoE trigger field about the size of a grenade's blast, any destructible item that is even partially in the field is entirely destroyed (ie; getting a part of a log destroys the entire log, barely clipping a wall will destroy as much as if directly hit with a rocket). It does not cause any damage to units, just cover. The cast distance scales with the users Will (see above).
	Pyrokinesis	Muton Elite Interrogation	Create non-damaging fire upon targeted area, which non-robotic aliens cannot cross. The cast distance scales with the users will (see above).
	Telekinetic Field	Ethereal Autopsy	Same as vanilla: it provides +40 defense in a wide radius, centered on the caster as well as revealing seekers Seekers.
5	Mind Control	Ethereal Interrogation	The caster makes an opposed will roll with the target at a +15 bonus. If successful, the target becomes controllable by the caster for 3 turns or until the caster is killed. Unlike in vanilla, alien weapons are no longer dropped intact if killed while under Mind Control.
6	Rift	Ethereal Mind Control	A highly damaging area effect attack that deals damage over time in an area and lasts for two turns. The base damage is equal to 8 in the round it is cast and 10 damage in the second round, with +1 or -1 to damage for each full 10 points of difference in Will between the caster and the target (down to a minimum of half the base damage). The secret to creating Rifts can only be found by Mind Controlling an Ethereal in battle; this must be done for every soldier that you wish to learn Rift. Casting it also requires the special Vortex armor be equipped.

Tactical Advice

Neural Feedback vs Regen Biofield vs Mind Fray

Mindfray could be a great tool to limit effectiveness of a single dangerous foe and decrease the threat of their aoe abilities. It also exposes the target for further psionic attacks. Neural Feedback on a high will soldier can do significant damage to psionic enemies and protect the squad from falling victim to further psionic abilities. Regen Biofield is another passive ability focused on curing acid and heal non-armor HP.

Distortion Field vs Psi Inspiration

Distortion Field is a passive ability that applies +10 defense to soldiers other than the psion in the area. Psi Inspiration is a great defensive buff, which eliminates negative will effects, but could also be a great tactical reactive tool to bring panicking soldiers back under your control.

Psi Panic vs Mind Merge

Psi Panic is an excellent way to disable key aliens when (read: not "if") you get overwhelmed, while Mind Merge can both protect the soldier from harm and improve his chances to both resist and deploy psionic powers.

Telekinetic Field vs Pyrokinesis vs Psychokinetic Strike

Three very strategic abilities, soldier class will be the primary decider, followed by playstyle. TK Field lasts one round and needs to be used, but is vastly more powerful than Distortion field; good for mid-range and/or high-move soldiers, so they can cast it to whoever else needs it. Keep in mind that it is centered on the caster, and that anyone not in the field should still be behind it: TK Field has an unfortunate habit of thusly drawing fire to any soldiers not under it's active protection, so have them at least in high cover or out of alien LoS.

PK Strike can turn any soldier in to an ersatz Sapper Engineer, or can be used when you don't want to blow a unreliable rocket or grenade on some cover (and/or don't want to risk killing the alien for either capture or artifacts). It's for when some cover needs to be destroyed right now. It's range is line of sight (and you can cheese it a bit around corners/cover that the soldier shouldn't be able to see around). In programming terms: any game asset 'prop' that is in the AoE bubble is entirely destroyed, even if it is only clipping into it, with the exception of walls, which will be destroyed to the rough equivalent as if they had received a direct rocket hit.

Pyrokinesis is adapted from the MEC's Flamethrower: it casts a non-damaging fire (that gradually destroys cover/objects: usually at the end of the next Alien Activity) upon a targeted area, and functions as a ground-denial ability: like normal flames from explosions, organic enemies (and non-fire-immune XCOM soldiers) cannot cross it, so it can be used to either block a choke point from enemy movement (ie: force Chryssalids and Berserkers to either stop or take a detour), deny high cover spots from enemies (block flanks, or keep EXALT from lining up in a Transmitter/Encoder capture area), or lock an alien from moving (be wary of any with jumping/flying abilities): in effect, a weak-willed Psionic's alternative to Psi Panic (though keep in mind it doesn't keep enemies from firing).

Mind Control

If you Mind Control an alien with health regeneration, keep in mind that it will heal at the end of your turn, be released (and take actions), then heal again at the end of it's turn.

Rift

To use Rift in battle, there are 4 requirements a soldier must meet:

Gain sufficient PsiXP
Have previously Mind Controlled an Ethereal
Successfully completed the training for Rift in the Psi Lab
And lastly, the soldier must wear Vortex Armor into battle. Otherwise, the icon for this ultimate attack will not appear, even if all other requirements are met.

Mind Controlling an Ethereal

Base Ethereal will is 135 on normal/classic, 155 on brutal, and 160 on impossible (they gain +15 will with their regen upgrade).

Ethereals gain +55 will at max research (1200 days in, the first +15 increase is at 420 days).

Ethereal pod leaders can also gain another +70 will.

In order for MC to have a 50% chance of succeeding your Psionic soldier must have 30 more will (buffs included) than the target. Psi Inspiration is a great way to improve the caster's will. Note that Mind Merge will likely not work.