Before you start the game, you must choose four difficulty levels: one for each of 4 aspects of the game. Unlike in other games, System Shock allows you to choose “0” in for this or that game aspect and turn it off if you don’t want it to be in the game at all.
- 0: There are a few enemies and they never attack you. They even die with a single hit no matter which weapon you use. Also enemies never respawn. Security cameras are shown on the map with red dots.
- 1: Weaker and fewer enemies. They attack you on sight but they never chase you. Less reinforcements. Security cameras are shown on the map with red dots.
- 2: Default difficulty setting. Default enemies, default damage, default reinforcements. Enemies start chasing you as soon as they learn about your presence. Security cameras are shown on the map with red dots.
- 3: More enemies and more reinforcements. Your damage is reduced to 2/3. Also security cameras aren’t shown on the map.
- 0: No e-mails, audio logs and that kind of in-game messages. Security level doesn’t prevent doors from opening, all doors are unlocked.
- 1: All audio messages are brief. No access cards are needed and security level doesn’t affect anything. You still need to hack some doors and solve other riddles to beat the game.
- 2: You will meet full messages. All access cards are required and security level needs lowering to access some areas.
- 3: As above, but SHODAN won’t wait forever for you to defeat her. You have 7 hours to beat the game.
- 0: All puzzles are already solved.
- 1: Puzzles are much easier to solve and always have several ways how to solve them.
- 2: Default puzzle level. Some wire puzzles have wires of different colors which means that they are harder to solve.
- 3: Wire puzzles have more slots and always have wires of different colors. Only one specific combination can be used for each wire puzzle. Net puzzles have more slots as well.
- 0: You have 30 minutes for each cyberspace session and always control your movement. No penalties for leaving cyberspace because of death.
- 1: You have 10 minutes for each cyberspace session and always control your movement. No penalties for leaving cyberspace because of death.
- 2: You have 5 minutes for each cyberspace session. You always move forward. There’s a 3-seconds penalty if you die when in cyberspace.
- 3: You have 2 minutes and 30 seconds for each cyberspace session. You always move forward really fast. There’s a 12-seconds penalty if you die when in cyberspace.