18+, read the BBFC rating
there is no reason
no
Call of duty 2 through call of duty4...they are more cartoon based than the later versions
It all depends on his/her maturity level. I first started play Call of Duty when I was 4 or 5.
Largely, it depends on the standing of the parents on whether or not their 9 year old should play Call of Duty or not. It should also be noted that the modern Call of Duty series is rated "M" for Mature 17+. This rating is not posted on the original Call of Duty, Call of Duty 2, Call of Duty: United Offensive, or Call of Duty 3 - in which are rated "T" for Teens.
17+
no
No only people who are 20 and older should play it.
Heroes 2 does not appear to be a call of duty game title, but many Call of Duty games are rated M and not T so it is really an adult game
18! or more
sure many are playing the mature games at that age
no but those are very old games u should get MW3 and enjoy the online play. Add: If your talking mw2 and mw3 then they are almost exactly the same game play. It doesn't matter.