Gameplay Proposals/Psionic warfare

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This is a simplified outline of how psionics should work, inspired by a longer proposal from Touchluck which can be read in the talk page.



Psionic warfare will become available through research on live aliens and XVI. Players will be able to research a psi-enhancing implant which allows their soldiers to access the alien psionic network and carry out attacks. When connected to the psionic network, soldiers are susceptible to psionic attack from aliens.

This document will outline research prerequesites, implant design, the mechanisms governing psionic warfare in the battlefield and related UI adjustments. For more detail on implant design and installation, see Proposals/Implants.


  • psi-warrior: psi-enabled Phalanx soldier
  • EMS: Effective Mind Stat (Mind modified by Morale)


See TODO/Roadmap#Tech_Tree.


  • Universal Serum
  • XVI-related event or research (exact item to be determined later)
  • 5 live aliens (must be retained throughout the research process)


A psi implant is just a regular implant that activates psionic powers for a soldier. We'll call that soldier a psi-warrior. It will not effect the rest of his loadout.

Psionic Warfare

A psi-warrior will be able to carry out psi-abilities on the battlescape, but they will also be susceptible to psi-attacks from aliens. Soldiers without the psi-enabling implant will not be susceptible to psi-attacks.

The success or failure of a psi-attack will depend on the Mind stat of the attacker and target, modified by the difficulty of the psi-attack and the target unit's current Morale. This means that it will be easier to carry out a difficult psi-attack on an alien with a low Mind stat. A suggested equation for the Effective Mind Stat (Mind modified by Morale):

EMS = Mind * ( Current Morale / Total Morale )

TU use for psi-abilities exposes a soldier to reaction fire in the same way any other attack would.

Note: We will need to rethink how the Mind stat increases and ensure it is balanced.


Some psi-abilities will not target specific aliens. These do not have any targetting requirements and can be performed at any time during the soldier's turn.

However, most psi-abilities will target a specific alien. These psi-abilities will require that the psi-warrior is aware of the alien's existence, either because they or a teammate has spotted them or because the alien's existence has been revealed by another psi-ability.

Psionic Power and Cooldown

Using a psi-ability will weaken a soldier's mental resistance (reduce Morale points). A certain amount of Morale will be restored each turn, but continued use of psi-abilities with no rest will, after 2-3 turns, make a soldier very susceptible to alien psi-attacks, or could cause them to panic, go berserk, etc.

The amount of Morale a soldier loses with each psi-attack is modified by their Mind stat.

The effects of many psi-attacks scale depending on the EMS.

Psionic Abilities (Phalanx)

Read Network: Scan psionic network to reveal alien presence. Weak psi-warriors may reveal only estimates on numbers. Stronger psi-warriors can reveal alien types, exact numbers, positions, equipment, health/morale status and skills/abilities stats.

  • Difficulty: Scaled (more info returned by better psi-warriors)
  • Targetted: No
  • Counter-attack Risk: None
  • Technical notes:
    • Each alien will be tested individually, and information will be returned individually. So, an alien with a low Mind stat may return lots of information, but a psi-warrior may detect nothing more than the presence of an alien with a high Mind stat. Example:
    • Weak psi-warrior scans for alien presence. There are 5 aliens in the map: two Ortnoks, two Shevaar and a Taman.
      • Ortnoks are psionically weak, so the scan returns all the information about them.
      • Shevaars have medium Mind stats. One Shevaar is a bit weaker, so the scan returns their position and health/morale status. The other is a bit stronger, so the psi-warrior is able to detect them, but does not know their precise location.
      • The Taman has a very high Mind stat, so the scan does not even return that it exists. The player gets no information about this missing link.
      • The psi-warrior believes there are 4 aliens on the map, it can identify the location of 3, and has full details of 2.
  • UI notes:
    • An ambiguous alien location model or particle will be needed to indicate a known alien location without knowing the alien. Another option is to not indicate an exact position, but all the center on alien function through the psionic hud window to approximate the location if alien type not identified (ie - they can tell roughly where it is, but not exactly).

Read Node: A Read Network attack that only targets a single, known alien. The attack is stronger because it is more focused and the psi-warrior is likely to retrieve more information than it did with Read Network.

  • Difficulty: Scaled
  • Targetted: Yes
  • Counter-attack Risk: None

Degrade Node: Attempt to weaken a target's Morale and cause it to panic. Stronger psi-warriors are able to cause more Morale-loss.

  • Difficulty: Scaled
  • Targetted: Yes
  • Counter-attack Risk: Medium
  • UI Notes:
    • When a target's Morale drops to 0, their status in the psi-window should say "Link Broken".

Mind Blank: When a target's Morale drops to 0, their mind can be blanked by an advanced psi-warrior. This will permanently sever their connection to the hive mind, turning them into a civilian.

  • Difficulty: Hard
  • Targetted: Yes
  • Counter-attack Risk: High (if performed on a target that hasn't reached 0 Morale)
  • UI Notes:
    • Target should disappear from the psionic HUD window.

Corrupt Link: Corrupt target's connection to the network, causing them to interpret all units as enemies. It will also reduce a target's Morale to some degree.

  • Difficulty: Medium
  • Targetted: Yes
  • Counter-attack Risk: High

Mind Control: Take control of a target. Each turn control is not severed, the psi-warrior will start with 50% of TUs and lose a set number of Morale points, modified by the Mind stats of both parties.

  • Difficulty: Very Hard
  • Targetted: Yes
  • Counter-attack Risk: High

Psionic Counter-attacks (Alien)

Some alien units will utilize psi-attacks (psi-specific units such as the Psi-Amplifier and a new advanced Taman). In normal play, alien psi-units will use Degrade Node, Corrupt Link and Mind Control.

However, whenever a Phalanx psi-warrior performs a psi-attack, they risk provoking a counter-attack. If an alien's EMS is higher than a psi-warrior's, the psi-warrior will suffer a Degrade Node attack.

Psi-controlled Aliens

Aliens under mind control will not be targetted by Phalanx soldiers using reaction fire.

XVI-effected Units

Civilians or soldiers on the battlescape that have been infected with XVI (when that is implemented) will appear just like aliens for all psi purposes.


A psionic hud window will need to be made that will allow the soldier to perform psi-abilities and access psi-related information. As a temporary solution for the current HUD, I suggest the following image.

Ui psionics.jpg

  • Firemodes: When clicked on, it will give a list of firemodes for psionics. Click on the firemode and then target the alien (no firing lines drawn).
    • Untargetted modes should have a button within the window to execute.
    • When a psionic power which can be targeted at a specific unit is clicked on, the cursor should change.
  • Network: When clicked on, it will list all known aliens with whatever information is available.
    • Click for more detailed information if stats/equipment were accessed.
    • It would also be nice to be able to target an alien through this window.
    • Click anywhere on window to go to the alien (important to know which Taman is in front of your soldiers, for instance).
  • Ideally, we would also have a Battlescape log somewhere that could, for instance, log the fact that a soldier's psi-attack failed and they suffered a counter-attack.


A suggested outline for completing this proposal in stages.

Mark I

A psi-implant can be researched after Universal Serum and Enemy on Earth. That psi-implant can be installed, activated and deactivated at the Hospital. In combat the soldier can perform Read Network (to identify alien numbers, location, type and, if possible, morale/health) and Degrade Link.


  • Implants completed
  • HUD support for psionic firemodes and network
  • Artwork for psi implant
  • Research text for psi implants
  • Code for psionic battle
    • Effective Mind Stat (Mind modified by MOrale)
    • Degrade Node
    • Read Network (basic information)

Mark II

Improve and balance the Mind stat increase. Implement alien counter-attacks.


  • Balancing
    • Ensure not every soldier is good at Mind, that only a few soldiers can improve above a certain limit.
    • Ensure there is a reasonable cap to Mind, so that no soldiers can be over-powered.
  • Code for psionic battle
    • Implement counter-attack risks for psi-attacks.

Mark III

Implement support in alien AI for psi-empowered aliens which can perform psi-attacks during their turn and not just in response to an attack.


  • Artwork
    • Special psi-enhancing alien that is very powerful
    • Particle effect that shows when a soldier or alien excutes a psi-attack.
  • Code for psionic battle
    • Support alien AI that uses Degrade link
    • Psi-enhancing alien should boost all aliens' Mind stat when present on battlefield and improve recovery rate for Morale

Mark IV

Implement enhanced Read Network/Node and all other psi-attacks.


  • Artwork
    • Particle effect that shows an alien under enemy control.
  • Code for psionic battle
    • Full Read Network/Node capabilities
    • Mind Blank
    • Corrupt Link
    • Mind Control

Mark V

Proper animations to illustrate psionic attacks, defenses, status, etc.

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