Discover some interesting facts about Counter-Strike Online.
- Although the first Counter-Strike Online version was released in 2008, one of the zombie models have a hidden banner displaying Copyright  NEXON & Valve Corporation. All Rights Reserved.
- Counter-Strike Online was only made available in Asia, until the popularity spreaded to non-Asian countries which prompted Nexon to release Counter-Strike Nexon: Zombies on Steam.
- Since Steam has not been popular in Asia, the name Counter-Strike Online has been allowed to be marketed. However in the West, the name was switched to Counter-Strike Nexon: Zombies in order to avoid misleading players into believing it as another official Counter-Strike game made by VALVE Software.
- Counter-Strike Online initially started off by implementing a highly-restrictive business model in order to encourage more players to spend money, by locking most of the default weapons (including the M4A1, AK47 and AWP) and zombie classes. However over time, players' complaints of being Pay-To-Win (P2W) have caused Nexon to revise their strategy by providing more freebies through various events.
- Counter-Strike Online was once featured in the World Cyber Games (WCG) 2012 games list, which caused it to receive a massive backlash from Western players. Ever since, it has not been seen in the 2014 roster before the closure of WCG.
- Contrary to popular belief, Counter-Strike Online/ Nexon Zombies runs on Counter-Strike: Condition Zero engine, rather than Counter-Strike 1.6's.
- Why has VALVE Software not sued Nexon for using the Counter-Strike brand? Because the former has leased the contract to the latter, and collects royalties in return. This is noticed with the VALVE logo appearing in all official intros and trailers.
- The original Counter-Strike Online (Korea) has been in service for over EIGHT years as of 2016.
- Nexon has invited a few famous South Korean celebrities to comprise different roles for their game. Examples include Jin Se-Yeon casting herself as both a Counter-Terrorist and Terrorist characters, and Ye Zi (or Ye Ji), a rapper from a five-girl group Fiestar as a zombie character.
- Counter-Strike Online runs on a Steam backend. If the player executes the console, the Steam logo is seen at the top-left corner of the window.