Call of Duty easy to play? I'd contest that on the grounds it most certainly isn't; I've witnessed newbies to it (people who I know face-to-face) who have spend days trying to get into CoD and failing due to the sheer difficulty; I know its hard for them because as soon as a player who is not even prestiged yet appears on the opposite team, they're mine; I seem to have a knack for destroying said individuals, causing them to leave after a game or two. And I know what its like to be that person; I took somewhere in the region of three months to get good at Call of Duty 4: Modern Warfare; I really wanted to and it took a lot of pain before I was good at; suffice to say those first three months were very unenjoyable; thankfully I had new games at the same time when I couldn't take it any more and needed a break from dying. And then of course since then, its been even less newbie-friendly, especially when they introduced "experienced players-only" stuff that raped at higher levels. In terms of multiplayer, I'd say its the worst out of the big shooter series out at them moment (save perhaps Gears...).
Battlefield is definitely worse in terms of accessibility, as is Halo (Halo is, in my opinion, one of the most newb-unfriendly games I've ever seen), but there are games considerably easier to get into than CoD.
