Water is a tool and substance that can be added to maps, found often in the campaign. It takes on a fair blue colored liquid by default, and can be swam through to avoid enemy bullets and defy the normal physics of dry gameplay. The water color can be changed for custom maps. Water can be used in various ways for decoration, combat, and convenient lifts that the player can swim up through, substituting for doors and walljumping.
- Water can be used to get away from drones fired from the Drone Gun CS-Virus, as the drones sink in water and do not move toward you unless the player is close to them.
- Water slows down most projectile types, including railgun shots. This can be used to dodge bullets easier.
- Water will also slow enemies down.
- Water dampens the sound of you moving, making sniping easier, as it will be stealthier. However, jumping in or out of water can give you away, especially if an enemy player knows where water is on the map.
- Water is sometimes used as stairs in some levels since you can continuously move up while in it.
- Water can be used to reduce fall damage and are sometimes used as cushions in some maps.
- Explosions from weapons other than the CS-BNG will become smaller and has a damage reduction underwater.
- An update in February 2014 now allows players to set water's color in their maps.
- It's possible to make a water area no longer affect game physics. Then it can be used for decorative purposes.
- There are two tactics involving water, these are water boosting and water skimming.