foxhound, feel free to correct my interpretation of this matter.
I've been doing a lot of reading - A LOT of reading - on the Elite "improve" pages and I've weighed in some of what Treyarch posted in their forums at BO.
What foxhound says about Treyarch and IW philosophies being diffferent is very important to this discussion - there ARE two different points of view.
Looking at the weapons, perks - all of those things, there is a VERY clear pattern to the IW philosophy. In fact, you can look back at MW2 and see this philosophy is a carry over.
IW stops short of encouraging spawn camping. In other words, they are all for it. If you can pull a spawn camp in IW eyes, you are the golden child.
To pull off a nuke in MW2, you pretty much had to get the AC130 or Chopper Gunner. Of those, the CG was ideal. Why? Because if you got one of those two, you could easily pull off a 14 kill streak (what was left needed to get the nuke) not because the CG could easily kill players, but because the CG could easily create a spawn trap. Reference Rust as an example.
Forward to MW3. Read ALL the information in the Elite Improve pages. IW outright states that the spawns are designed to be fluid. Now, most of you will never get the importance of this. So Elite explains it in more simple terms "If you move too far into an enemy controlled area, the spawn is going to change."
In other words, if you want the opposing team to remain spawning from a certain point, then do not get too close. Well that obviously means "Yes, you can DEFINITELY pull off a spawn trap."
Now, before everyone cries and whines that this is a stupid idea, wait just a minute. Because holding a spawn trap in MW3 is harder than ever before. You now have the Support Strike package which can easily take out a spawn trap. Set the package up with Ballistic Vests, SAM Turret, and Stealth Bomber and you can whip out a spawn trap pretty easy. There's other combinations that help with this, as well.
IW can't tell you how to play the game. You have to figure these things out for yourselves. But definitely they have designed the game in a way that at least rewards spawn camping.
Another clue?
Your kill streaks start all over once you've hit your last reward. If I am set up with a 4-5-6 Assault Strike package kill streak reward, as soon as I call in my 6th kill reward, I'm already working on my #4 reward again. This goes on infinitely.
So. If I get a six kill streak, I've got 3 rewards I can call in. I don't die. I'm not at 12 kills. I have 3 more rewards I can call in. At 18 kills I get 3 more rewards.
I understood that kills brought by kill streaks were not supposed to count toward more kill streak rewards ... but that's not what I've been seeing. I've used Predators to get Attack Helos. Next thing I know, I'm calling in a Reaper ... I had a match where I called in 3 Predators, 3 Helos, and two Reapers before I was killed. After the second Predator, I might have killed with a knife or gun 4 or 5 guys.
Oh, and I was so wishing in that match that we had caused a spawn trap. We had not but it was right after game release so no one knew how to react to the load out I had.
Anyway, the point is MW3 may not encourage spawn trapping, but they certainly reward spawn traps. Futhermore, I can't think of a single map where a spawn trap is not possible - fairly easily possible, at that.
BUT, like I said, there are ways to bust a spawn trap. Support makes busting a spawn trap pretty easy to pull off. Not only that, but the Death Streaks also help in busting a spawn trap, as well.
Black Ops, on the other hand, demonstrates very easily they don't like spawn traps: Kills by kill streak rewards did not count toward more kill streak rewards. Every map had a way to flank yourself out of a trap or to take out campers. The SAM turrets reacted far faster to enemy aerial support than they do in MW3.
I think, from what I'm reading in official literature from IW, spawn trapping is definitely a viable strategy in MW3
