Hey, I thought we should help 343 with some Ideas for multiplayer so i decided to help us get started. I’ll add good suggestions to these posts and address problems with these ideas. If you don’t feel like reading everything I wrote, just leave your suggestions/ideas below 
For Halo 4 to be successful, it needs to have a lot of changes. However, 343 needs to make sure the core mechanics of the Halo games are kept intact and improved. We will be addressing the multiplayer in this thread.
Here are some of my general ideas we can add many new features, but stay true to Halo’s fast paced action, addictive gameplay, and overall feel.
Ranking: Their NEEDS to be ranked vs unranked playlists. Even the casual players lose out with a lack of ranked playlists because they will get matched up with players who utterly demolish them. For the most part, it should be modeled after Halo 3’s, but it doesn’t need to be 1-50 as long as similarly skilled player are matched up together. I think that they should be add in a detection of how the player is fairing in his games. If they are consistently out/under-performing the people they are playing, the rank should loosen up until they find a more fitting rank. This would prevent rank lock ups and make de-ranking less effective. The most important thing this ranking system would accomplish is pairing similarly skilled players together, because it would mean that the skill gap could be large while the game would still be accessible to casual players.
Sandbox:
Strafing: It plays an important role in the sandbox because it is one of the primary factors in effective kill times. As strafing becomes more effective at throwing off bullets, the kill times start to go up. Halo 4 needs to have a very effective strafe, powerful weapons, and low aim assist to be appeal to a wide player base. The casual players would still have faced paced gameplay because the weapons are strong and their accuracy should be good enough to deal with the undeveloped strafes. The more experienced players will be in a constant battle to get their weapon’s potential kill times while strafing to prevent their opponent from doing so.
In every game since Halo 2, there has been a go-to “Utility” weapon. This weapon was effective in most scenarios and how good a player was depended on his efficiency with this weapon. While a weapon like this is not inherently bad, it made most of the other guns in the game useless. This was somewhat justified since it was “harder” to use than the other weapons in terms of aim assists and magnetism, but unfortunately was so much more powerful that you were better off using it even if you were bad with it. I will draw out a sample sandbox below to demonstrate the advantage of decentralizing the power from a utility weapon.