Metacreative Barrier

Metacreative Barrier or Psi Barrier is a Tier Five defensive Psionic Power in System Shock 2.

Overview
This Power summons a Wall of Psionic force on the same height as and directly in front of the player. The Wall blocks all physical objects, including enemies and their projectiles.

It lasts 4 minutes or until destroyed. With PSI levels 1-5 it has 150 hit points, and each PSI level over 5 grants an additional 50 HP to the Barrier's health. Metacreative Barrier is one of the few Psionic Powers that benefit from PSI levels greater than 8 (up to PSI 10), however these can only be reached using Psi Overloading.

Hit Points Table
* Available only using Psi Overloading.

Strategies

 * This is a good combat avoidance Power. The Ability synergizes with Soma Transference by trapping an enemy with the Barrier and draining all of the foe's Hit Points away. However, the enemy typically needs to be close to the outer side of the Wall to be targeted. Ideally, a small gap between the Psi Barrier and the nearby surfaces should be left for easy aiming. Alternatively, it's possible to mantle the Wall and drain enemies' health from there.
 * Standing on the Barrier also allows you to use Ranged Weapons against blocked/trapped enemies.
 * Should an enemy get too close, its projectiles can get on the other side of the Barrier. This it is recommended to cast two Psi Walls with a small distance between them.
 * This Power is effective in the final battle against SHODAN, especially during hacking shield's Terminals. It can block her Avatars' Energy shots with ease while you hack. Make sure you place more than one Barrier though, as their damage is quite high. Also, mind the electrocuting floor beneath each Terminal when placing the Barriers. To avoid it, either drop a bigger item (like an Armor) in front of the Terminal and climb/mantle upon it, or cast a very useful Energy Reflection Power to absorb some of the damage.
 * This Psi Power can be used to easily reach normally inaccessible places. Psi Walls are climbable, allowing to reach great heights with enough caution. Because of this, they combine greatly with Instantaneous Quantum Relocation (Psi Teleport), creating safe spots to rest and snipe. Experimentation is encouraged!

Trivia

 * Identically looking Psionic Wall is created in front of the Umbilical on the Command Deck of the Von Braun by Anatoly Korenchkin's Psi Reaver form. However, this Wall does not wear out and cannot be damaged. It disappears only after Korenchkin's Psi-Brain is destroyed.