System Shock 2/Tech

Hack
The hack skill allows you to access and interact with computer systems. As the skill level increases, the chances of hacking a system successfuly improve, and the possibilities of a critical failure also decrease.

When hacking a system, you will spend a small amount of nanites, and will be presented with a grid of cells. Before attempting a hack, statistics concerning the chance of successfully activating a given cell are shown - in addition, cells marked red will cause a critical failure if you are not successful. To complete the minigame successfully, get three lit cells in a row.

The results of a critical failure may vary - it may set off an alarm, damage the device you are trying to hack, or cause it to explode.

It needs to be upgraded to at least level 3 in the late game, in order to obtain an item essential to the plot.

Repair
The repair skill allows you to fix damaged or jammed items.

As with hacking, you will be presented with a grid of cells. A critical failure causes the item to be permanently destroyed.

Modify
The modify skill allows you to improve the performance of your weapons, as described within the description of the weapon.

As with hacking, you will be presented with a grid of cells. A critical failure will damage your weapon.

Maintenance
The maintenance skill (abbreviated to Maint) gives a better result when you use maintenance devices on your wepaons. While you can still maintain weapons without the skill, it will only improve the condition by 1 unit. Each point invested in the skill increases the effect by 1 additional level.

Research
Research allows you to identify certain unusual items you may discover. To research an item, you can right-click on it in the inventory, and your cybernetic software will attempt to analyse it. From time to time, it may request a certain chemical in order to continue research, as listed in the description of the item. These chemicals are found in storage areas located throughout the ship.

It needs to be increased to at least level 1. While Shodan will give you the cybernetic modules to research it, it is still possible for the game to be unwinnable if you spent too many on a higher difficulty level.