Psycho-Reflective Screen

Psycho-Reflective Screen or Psi Shield is a Tier One defensive Psionic Power in System Shock 2.

Overview
This Power provides 15% defense against damage of almost all types. The only excluded sources are radiation, toxins and drowning. Its duration depends on the player's PSI and equals 30 seconds × PSI + 20 seconds. Note that Overloading this Power does not affect it in any way!

Analysis

 * It is one of the first Psionic Powers the player is likely to unlock due to its low requirements and wide usefulness.
 * It's possible to learn this Ability on Year 1, Mission 3 of OSA Agent's Tour of Duty.
 * This Power is extremely practical because it affects all types of combat damage and almost all of non-combat.
 * Defense given by the Psi Shield stacks with that of physical Armors and the WormMind Implant.
 * Psi Shield's defense also accumulates with other defensive Psi Abilities (one or more):
 * Psycho-Reflective Aura for defense against most types of damage
 * Energy Reflection for protection against energy-based damage
 * Other defensive Psi Powers complement the Psi Shield:
 * Neural Decontamination vastly shields against radiation absorption
 * Neural Toxin-Blocker blocks all toxin intake
 * It should be cast before all other Psionic Shields, as it lasts the longest.