Played every hour of the Call of Duty series? Think you've seen it all? Think again, soldier, we list the secrets hidden in the world's biggest franchise... 1. THE QUAKE CONNECTION Since Call of Duty 2, the series has used the IW Engine. This began life as a heavily modified version of the Quake 3 engine - under license from legendary FPS pioneers id Software. The engine was also used for the Quantum of Solace spin-off game. 2. ROCK AND ROLL In Call of Duty: Finest Hour, Sergeant Starkey - who we met during the attack on a German base in Tunisia - was voiced by geordie AC/DC lead singer Brian Johnson. His father was a Sergeant Major in the British Army, and he based his voice on him. 3. UNUSED CONTENT PC modders digging deeply through the files of a wide number of the Call of Duty games have found references to, among other things, an unused mission set aboard the International Space Station in Modern Warfare 2. 4. STRIVING FOR AUTHENTICITY Always striving to add the upmost authenticity to their games, while they were developing Call of Duty 4, the developers attended a live fire training session at the Twentynine Palms military base in California. They stood next to Abrams tanks as they fired so they could recreate the sensation of both noise and vibration in the game. 5. TIME TRAVELLER Captain Price, who has since become one of the CoD's most loved characters, appeared in both Call of Duty 2, set in 1940s WW2, and Call of Duty 4, set in the modern day. Any explanation has been left ambiguous. A distant relative? 6. RAPID DEVELOPMENT Santa Monica-based developer Treyarch only had eight months to put together Call of Duty 3, the first game in the series to appear on all of the current generation consoles, and the first in the core numbered series not to be released on PC. To execute this gargantuan feat they used their own in-house NGL engine, which they had previously used for Call of Duty: Big Red One on PS2 and Xbox. 7. MUSIC TO OUR EARS Perhaps the most famous composer to work on Call of Duty is Michael Giacchino, who created the music for the original Xbox game Finest Hour. He's also worked on Lost, Fringe, Mission Impossible III and Star Trek (the movie). 8. DLC EASTER EGG The first letters of the names of each map pack released for Call of Duty: Black Ops spell out the word 'FEAR' - First Strike, Escalation, Annihilation, and Rezurrection. This is likely because of the heavy focus on Zombies mode 9. MEDAL OF HONOR VETERANS The original Infinity Ward team was made up of developers who'd worked on the Medal of Honor series. Activision gave them the funding to splinter off and create a rival to EA's popular first-person WW2 series. 10. GERMAN CENSORSHIP In the German version of Modern Warfare 2, harming any civilians in the infamous, tabloid-bothering No Russian airport massacre would result in an instant mission failure. And all swastikas have been removed from the WW2-based games. 11. VOICE WOES Actors playing the Call of Duty characters have to spend hours recording what the developers call 'battle chatter' (All that battle-apt stuff like "Attack!" and "On my position!"). 24 star and Sgt Roebuck voice actor Kiefer Sutherland said after his voice over session on CoD: World At War that he "hadn't shouted that much since he was married". 12. FAMILIAR VOICE Billy Murray, the voice of Captain John Price, is perhaps best known in the UK for playing DS Don Beech in The Bill and gangster Johnny Allen in Eastenders. While recording dialogue for Call of Duty 4, he had no idea that the game would become such a worldwide success. 13. EXPERT HELP For Black Ops, Treyarch consulted special forces veterans from both sides of the Cold War: a US Vietnam major, and former Soviet special forces man Sonny Puzikas. 14. PLAYER CHARACTERS There have been just under 100 controllable characters in the Call of Duty series, from John F Kennedy to nameless chopper gunners. Of the entire series, PSP's Roads to Victory has the most, with an impressive cast of 10 playable characters. 15. STONES SALES BOOST After the prominent use of the Rolling Stones song Gimme Shelter in Black Ops, it had a popularity spike, selling 11,000 extra copies on iTunes after the game's release. Other Vietnam era music used in the game saw a similar increase. Source - CVG
