Psionic Ability or PSI is one of the basic statistics in System Shock 2.
The maximum effective Psionic Ability level is 10, although most Psionic skills benefit from a PSI up to 8. The player can only permanently upgrade Psionic Ability to level 6, while the next two levels require a combination of the following items/Psionic Disciplines:
- A PsiBoost™ Implant (+1)
- A Psi Booster (+1)
- A WormSkin Armor (+2)
- Recursive Psionic Amplification (RPA) (+2)
Overloading a Psi Power casts it with a bonus of +2, to a maximum effective PSI of 10 (player needs to have PSI 8 already before casting to reach PSI 10). It is not possible to reach PSI 9 or 10 without Overloading.
Psionic Ability increases the Psi Points of the player and influences the duration/effectiveness of Psionic Disciplines. The amount of bonus Psi Points given depends on the difficulty:
Psionic Ability vs maximum Psi Points Table
|Psionic Ability Level||Easy||Normal||Hard||Impossible|
- Maximum Psi Points of the player change when upgrading the PSI stat, but they are not affected in any way by the items, RPA, nor overloading.
- The only other thing affecting the player's maximum Psi Points is unlocking main Tiers of Psi Powers. Each Tier adds to the max Psi Points a value of 2x the level of the Tier (no matter the skill level), e.g. Tier 3 adds 6 to the max Psi Points. The total bonus to max Psi Points is thus 30.
|System Shock 2 Character Builds|
|Classes||Marine • Navy • O.S.A. Agent|
|Statistics||Strength • Endurance • Psionic Ability • Agility • Cybernetic Affinity|
|Technical Skills||Hacking • Repair • Modify • Maintenance • Research|
|Combat Skills||Standard Weapons • Energy Weapons • Heavy Weapons • Exotic Weapons|
|O/S Upgrades||Cyber-Assimilation • Cybernetically Enhanced • Lethal Weapon • Naturally Able • Pack-Rat • Pharmo-Friendly •|
Power Psi • Replicator Expert • Security Expert • Sharpshooter • Smasher • Spatially Aware • Speedy •
Strong Metabolism • Tank • Tinker