Sven Co-op (abbreviated as SC) is a co-operative game mod of Half-Life for the PC. Sven Co-op is a direct modification of Half-Life, as well as many other Half-Life mods, that provides online co-op compatibility. As of Sven Co-op 4.8, released on June 30, 2013, Sven Co-op features co-op gameplay for over 15 different mods.
The game was originally created and released by Daniel 'Sven Viking' Fearon as a small mod with two single player maps and the game configured to allow NPCs in the game (by changing a CVAR to allow them to exist in the multi-player game mode). Sven Co-op was released on January 19, 1999 - before Valve's Team Fortress Classic - and is therefore the oldest Half-Life mod in existence that is still in development. It has since grown to become a full blown mod, with a full team, and one of the most played games on Steam as of September 18, 2006, excluding the official games by Valve.
Since Sven Co-op is heavily based on the original Half-Life, it is essential that the player is at least familiar with Half-Life and its controls, and it is recommended that they have completed Half-Life's Hazard Course tutorial level. The single player campaign of Half-Life is supported by Sven Co-op, but in a slightly altered form to create a better challenge for co-operative play.
Sven Co-op's levels are set as missions and are generally separate from each other. Many missions span several maps, and some are collected together in a series. The aim of most levels is to reach the end or to achieve an objective—obtaining a high score is not the focus. Map scenarios can be set in Black Mesa, cartoon worlds, World War II, fantasy maps, modern urban warfare or any other kind of theme and time period the mapper chooses. This creates an extremely diverse game play environment, as virtually all other games have a fixed theme and time period.
Some of the major features of the mod include:
- An in-game monster/player info system that displays information about NPCs and other players the player is looking at (the info system for monsters only can be disabled for realism).
- The ability for mappers to create allied monsters to assist players and follow commands issues by players such as following the player, or attacking an enemy.
- The ability for mappers to individually customize the models and sounds of NPCs and weapons.
- Ability for a .cfg file which allows mappers to specify the physics (gravity, player walk speed), what weapons the player(s) spawn with, and the damage of the weapons and monsters within the map.
- A medkit 'weapon' that is used to heal and revive other players and friendly NPCs.
- Significant improvements to the artificial intelligence of the original Half-Life NPCs.