As computer games have increased in popularity, gameplay has gained renewed attention across many research fields. Yet one of the most popular game mechanics - perhaps the most popular - has received little attention. Developing from existing accounts of expert skill, this talk examines running and shooting in Counter-Strike, one of the most popular of collaborative online games. While Counter-Strike at first appearance may seem an unsophisticated pursuit, players display complex skills developed through many hours of concerted play. Participating in and analysing videos of gameplay, we examine Counter-Strike as an example of expert technology use. Players move beyond physical dexterity to chain their movements with the online environment. They develop a sense of the terrain of play as contingent to the state of play, rather than as static spatial knowledge. The game's design also makes available to players an analysis of their successes and failures as an integral part of play. From these observations I draw concepts for better conceiving of expert skill, alongside some general suggestions for supporting expert use.