Modify is one of the technical skills available in System Shock 2.

This skill allows to modify ranged weapons to make them more effective. Each ranged weapon has two Modification Levels in addition to the base unmodified Level. The effects of modifications are weapon specific. Usually, they increase the damage along with other effects such as enlarged capacity, reduced reload time or ammo consumption. Modifiable weapons have a “MODIFY” panel on the side of their MFD display. Modify skill requirements depend on the Modification Level of the target weapon:

Modification Table

Weapon Modification Level Skill needed Nanite cost Initial Difficulty Safety Interlocks Damage Other Effects
Talon M2A3 .45 Caliber Pistol 1 1 20/10* 60% 1 +10% Clip Size 24
2 3 20/10* 70% 3 +25% Reload Time -67%
Shotgun 1 1 20/10* 70% 2 +10% Reload Time -67%
2 3 20/10* 80% 2 +25% Kickback -67%
M-22 Assault Rifle 1 2 20/10* 90% 3 +10% Reload Time -67%
2 4 20/10* 110% 3 +25% Clip Size 72
Apollo H4 Laser Pistol 1 2 20/10* 100% 4 +10% Capacity +50%
2 4 20/10* 120% 4 +25% Consumption -33%
Dual-Circuit EMP Rifle 1 3 20/10* 105% 3 +10% Capacity +50%
2 5 20/10* 125% 3 +25% Consumption -50%
Projectile Speed +50%
TC-11 "Brick" Grenade Launcher 1 1 20/10* 100% 4 +100% Clip Size 9
2 3 20/10* 120% 4 +128% Reload time -67%
Projectile speed +50%
Stasis Field Generator 1 2 30/15* 115% 5 - Projectile Speed +100%
2 4 30/15* 135% 5 - Consumption -50%
Fusion Cannon 1 4 40/20* 110% 4 +10% Clip Size 80
2 6 40/20* 130% 4 +25% Consumption -50%
Viral Proliferator 1 3 75/37* 120% 7 +10% Clip Size 18
2 5 75/37* 140% 7 +25% Consumption -50%
Annelid Launcher 1 2 50/25* 120% 6 +10% Clip Size 18
2 4 50/25* 140% 6 +25% Projectile Speed +100%
* Modification cost in Nanites when using the Tinker O/S Upgrade.


The top of the modify MFD display shows the effects of successfully modifying the weapon. The bottom of the screen describes the Initial Difficulty, any bonuses that are applicable from the Modify skill, Cybernetic Affinity statistic, Modification Software and equipment (ExperTech™ Implant), the resulting final difficulty and the number of Safety Interlocks. On the far right of the Modify display is the cost in Nanites and a button marked Start. Click Start (or Reset, if you’re already modifying) to pay the cost in Nanites and Start (or Restart) the Modify process. The Nanite cost is halved with Tinker O/S Upgrade. The inferface will show a connected set of squares, outlined either in cyan or red. The cyan squares are the ones you have identified as “safe” while the red squares are dangerous “Safety Interlocks”. The number of dangerous squares depends on the CYB statistic, the type of the weapon and sometimes its Modification Level.

Every point of Modify skill decreases difficulty by 10%, as does the ExperTech™ Implant and each level of Modification Software. Every level of CYB decreases difficulty by 5% and additionally reduces the number of Safety Interlocks by 1.

To successfully Modify the weapon, you must get three squares to light up in a straight line. Click on a square to attempt to light it up. The percentage in the upper left of the MFD is the final difficulty, or in other words, the chance you fail to light a square up (this percentage can never fall below 15%, no matter how high your Modify skill, CYB stat and bonuses are).
If you fail on a “safe” node, it turns dark and its state cannot be changed until the Modification process is reset.
If you fail on an Safety Interlock, however, you critically fail the Modification. Critical failures cause weapons to jam and be in need of Repair (they are unmodifiable until repaired).

The French-Epstein Device can be also used for one-time instantaneous increase of weapon's Modification Level.


  • Modification Level 2 damage increase is relative to the base Modification Level (i.e. unmodified weapon).
  • Grenade Launcher damage bonus does not apply to Disruption Grenades.


  • The Modify skill can be considered a low-value skill in a single-player game, especially on the lower difficulty levels. There are 7 French-Epstein Devices in the game on Easy and Normal difficulties, 6 on Hard and 5 on Impossible, most of which are found before the Rickenbacker. Six F-EDs allow full modification of 3 weapons.
  • In cooperative game (especially with 3 or 4 players), it may be more than useful for one player to get expertise with the Modify skill and preferably Tinker O/S Upgrade. This way, the whole team can get fully upgraded ranged weapons even with the limited number of the French-Epstein Devices found in the game.


  • The Tri-OS part of the display (located on the right side, between the Modification cost and the Start/Reset button) used to be active in earlier versions of the game, during its development. That area was highlighted if the player had any Modification Software installed, with the small dark window displaying the current version of the Software. This is still depicted in some versions of the game manual. In the final product the Tri-OS area is still a part of the displayed MFD but is dimmed and inactive.

See Also

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