Do Call of Duty games have blood in them?

Yes, they also have very many swear Words and include adult themes.

IMPROVED ANSWER:

They all have blood in them, but not all of them cuss like the other dude said.

Call of Duty 1-3 dont have that many Words in them. they also have NO adult themes.

COD 6, A.K.A. Modern Warfare 2, says the F Word once at the end, and a little mild language throughout the rest of the game.