If i trade with someone from russia. will i be able to play the game?

You might lose your steam account as a result of such actions therefore, playable or not, I'd advise against it.

Your steam acc can be banned from trade forever for that things...

i thought those trades were allowed... not in a massive amount of course
what if someone from Russia wants to gift you a game?

banned? for simple trade? LOL. go dai peeps.

in soviet russia games play u! so better not do it!!

You can't get banned if you for example order some russian guy to buy a game and then trade that for TF2 keys. The russian guy can however get banned. This is not against the TOS, and if it was trading would be really risky, since a giftable copy MAY have been originated from Russia from the beginning, and therefore you could be banned. Read it all if you misunderstood, you CANNOT GET BANNED FOR TRADING WITH RUSSIANS! Trying to use a VPN to activate a region restricted game, or to login to the russian steam to buy a game etc etc is however bannable.

EDIT: CoD is region locked, the russian you want to trade with is obviosuly scamming you, or you are just stupid trying to bypass the region restriction.

EDIT2: Apparently it's not locked, or... uh

I think the best rule is, if you don't know how the region locks work and don't want to figure it out for yourself then you would be safest to just avoid them.

Anyone got an answer for my question or ?

If the game is not locked, then no. You would be banned for using VPN to activate (if the game was locked)
Trust me, I'm a trader and got a bunch of games from Russia.

Yep that particular one should work fine but you better ask the rus side to check the game page if you try to buy something else(trust me im russian)

Depends, the only RU entry for MW2 in the database I found is retail key and looks like it isn't region locked, but there's always a risk with the keys. If it's a tradable copy, you should be fine.

Some games are region-locked and you can't activate them in any country, excluding Russia. All the others can be traded whoever you want. I live in Russia and trade some games to my american-european friends, none of us never had a problem with that.

Also, if we talk about MW2, steam copy of the game will be activated as usual, but don't accept retail keys of the game, you won't be able to activate them.