Multiplayer and what has been confirmed:
Spartan Points
Spartan Points are similar to the Black Ops currency system. A player earns Spartan Points every time he/she ranks up. These Spartan Points will allow the player to purchase armor abilities and other things a player would use in the game.
Spartan Ops
Spartan Ops will be very similar to Spec Ops from the Call of Duty series except that they will have a storyline to the missions. This game mode will replace firefight. 343 Industries will add another mission every week to a month to bring player back to Halo 4/. Not much else in known to this game mode. The game mode will also be solo, or two, three or four player missions.
Default Sprint
Yes, there will be default sprint to use in the game. Since 343 Industries wants to speed up the game a lot they are using sprint as a default armor ability. However I am not sure if you can use it with another power up. For example, a player could use sprint, and have Hologram and use them both at the same time. This would probably mess with the controls a lot.
Joining during games
In all the other Halo games when someone backs out no one can join back and the game will remain without that player until the end of the match. This could be a bad thing and a good thing. One reason it could be a bad thing is that players will join a match and the match will end ten seconds later. However one reason it could be a good thing is so people don't have to worry about their whole team quitting the game in Big Team Battle. However a lot of people are unsure about this because of the bad reason explained. People are also worried this will be too similar to Call of Duty.
No Respawn Delay
To make the game faster pace 343 Industries made the game to where you can just double tap X to respawn. A lot of people are worried about this because in Capture the Flag. For example if someone is about to kill the flag carrier and dies, usually the flag carrier can just run away with the flag with enough time to recharge his shields. But with no respawn delay the flag carriers shields won't recharge enough and he/she could be killed easily. This reason could also be the same for any other game mode. This is a good reason because it can make the match faster pace.
Forerunner Vision (X-Ray vision)
Forerunner vision will obviously let the player see through walls to spot campers with a shotgun or Energy Sword (The Energy Sword will probably be replace with a similar close range weapon). However no power up is perfect and every power up has a disadvantage to it. For the Forerunner vision it will make a noise alerting a player where he is.
No Armor Lock
There will be no more armor lock. I am not sure of the exact reasons but the logical reasons could be that people use them to charge their shield even when they are shot at. There is also a glitch with the armor lock which allows the player to do what I call an "EMPummel" This is when a attacking player is close enough to the player in the armor lock. When the player in armor lock deactivates it, it sends a wave of EMP (Electromagnetic Pulse). This EMP is sent in a very small radius. Then the person that was attacking the player in armor lock would try to pummel the other player but it wouldn't work because the game still thinks the player that was hit with melee is still in armor lock. So the player that exited armor lock had already sent out an EMP to the other player and he could melee him for the kill. So technically the player in armor lock could hit the other player with one hit unless the other player was at a distance or strafing around the armor locked player.
The paragraph above could explain a reason for no more armor lock.
However, no armor lock could be a bad thing. On a average day of playing Halo: Reach I get stuck with about thirty Plasma grenades (if I was playing for four hours on Invasion). Usually I would pick armor lock for the shotgun. So the times I have died from Plasma Grenade is about 10-15. The other 15-20 times I survived because of armor lock. Armor lock also has saved me many times from Ghosts, Wraiths, Banshees, Revenants, etc.
You CAN NOT play as Sangheili (Elites) anymore
Enough said. There will be a new species of players can play as in multiplayer. Not much is known about what type of creature the player.
Spartan Points are similar to the Black Ops currency system. A player earns Spartan Points every time he/she ranks up. These Spartan Points will allow the player to purchase armor abilities and other things a player would use in the game.
Spartan Ops
Spartan Ops will be very similar to Spec Ops from the Call of Duty series except that they will have a storyline to the missions. This game mode will replace firefight. 343 Industries will add another mission every week to a month to bring player back to Halo 4/. Not much else in known to this game mode. The game mode will also be solo, or two, three or four player missions.
Default Sprint
Yes, there will be default sprint to use in the game. Since 343 Industries wants to speed up the game a lot they are using sprint as a default armor ability. However I am not sure if you can use it with another power up. For example, a player could use sprint, and have Hologram and use them both at the same time. This would probably mess with the controls a lot.
Joining during games
In all the other Halo games when someone backs out no one can join back and the game will remain without that player until the end of the match. This could be a bad thing and a good thing. One reason it could be a bad thing is that players will join a match and the match will end ten seconds later. However one reason it could be a good thing is so people don't have to worry about their whole team quitting the game in Big Team Battle. However a lot of people are unsure about this because of the bad reason explained. People are also worried this will be too similar to Call of Duty.
No Respawn Delay
To make the game faster pace 343 Industries made the game to where you can just double tap X to respawn. A lot of people are worried about this because in Capture the Flag. For example if someone is about to kill the flag carrier and dies, usually the flag carrier can just run away with the flag with enough time to recharge his shields. But with no respawn delay the flag carriers shields won't recharge enough and he/she could be killed easily. This reason could also be the same for any other game mode. This is a good reason because it can make the match faster pace.
Forerunner Vision (X-Ray vision)
Forerunner vision will obviously let the player see through walls to spot campers with a shotgun or Energy Sword (The Energy Sword will probably be replace with a similar close range weapon). However no power up is perfect and every power up has a disadvantage to it. For the Forerunner vision it will make a noise alerting a player where he is.
No Armor Lock
There will be no more armor lock. I am not sure of the exact reasons but the logical reasons could be that people use them to charge their shield even when they are shot at. There is also a glitch with the armor lock which allows the player to do what I call an "EMPummel" This is when a attacking player is close enough to the player in the armor lock. When the player in armor lock deactivates it, it sends a wave of EMP (Electromagnetic Pulse). This EMP is sent in a very small radius. Then the person that was attacking the player in armor lock would try to pummel the other player but it wouldn't work because the game still thinks the player that was hit with melee is still in armor lock. So the player that exited armor lock had already sent out an EMP to the other player and he could melee him for the kill. So technically the player in armor lock could hit the other player with one hit unless the other player was at a distance or strafing around the armor locked player.
The paragraph above could explain a reason for no more armor lock.
However, no armor lock could be a bad thing. On a average day of playing Halo: Reach I get stuck with about thirty Plasma grenades (if I was playing for four hours on Invasion). Usually I would pick armor lock for the shotgun. So the times I have died from Plasma Grenade is about 10-15. The other 15-20 times I survived because of armor lock. Armor lock also has saved me many times from Ghosts, Wraiths, Banshees, Revenants, etc.
You CAN NOT play as Sangheili (Elites) anymore
Enough said. There will be a new species of players can play as in multiplayer. Not much is known about what type of creature the player.