So for those who aren't familiar, I made a successful Megathread of the same topic in the BO forums but now its MW3's time!
If you wish to put a tip or trivia just post a valid info about a tip or trivia in this thread. Posters will be credited.
Tips and Trivia
1. It is not reccomended to use Grenade Launchers or Launchers due to the fact of the smaller blast radius
2. Riot shields can also deflect bullets if shot enough.
3. Changing classes will make you lose progression on the pointstreak you're having
4. During the use of a juggernaut pointstreak, you will not regenerate health until your character reaches 500 hp, where it will regenerate to that point very slowly over time.
5. When facing a fire fight, the first thing to do when using a riot shield is to crouch. It makes your feet protected from being toe snipped.
6. EMP does not only jams your radar, but also renders your equipment, red dot sights and heartbeat sensors useless. This can be countered by using Assassin Pro
7. Assassin Pro Perk does NOT hides you from enemy aircraft and killstreaks. Only Blind Eye Perk will.
8. Support strike packages does not go away even after death so it is ideal for beginners and every team player out there.
9. You will receive a MOAB killstreak reward ,in any Pointstreak class, if you get to 25 kills using only your combat weapons (killstreaks reward will do nothing to add the streak)
10. In Spec Ops Survival, try using the Air Support to easily take out juggernauts
11. A pistol with tact. knife will make you the fastest knifer in the battlefield.
12. Also, the XM25 can be used as a shotgun. Just slap on stalker and blast shield, aim down and set the distance to one. Run around and have fun with your explosive shotgun .(by Padiego)
13. You need to be close to your Remote Sentry to use it remotely. (ironic isn't it)
14. In Spec Ops Survival, make sure not to camp at a certain place when there's a juggernaut especially during the later levels
15. It is advisable to use a pistol when you equipped the riot shield especially with a tac. knife. This is because the time taken for a pistol to be deployed is always faster than pulling out other weapons.
16. The Blind Eye perk will still make you visible on the Remote Turret Screen although harder to detect without the red box
17. It is not wise to use the hybrid sight or the HAMR scope on a weapon with high recoil
18. Dont always trust the stats in create-a-class.
19. Shotguns has less spread (more pellets at where your aiming) if you aim down the sight of your shotgun.
20. The Delta Squad is only useful during the early round, they go down pretty quick after round 15+
21. Bouncing Betties can be overcome by proning.
22. Unlike tomahawks, throwing knives can stick to walls and object including riot shields
23. In Survival, after later rounds, the enemy will plant claymores at certain areas
24. When the riot shield is used, throwing any material will put you out of cover
25. The specialist strike package will reward you ALL the pro perks and proficencies once the OMA mode is achieved. The only exception is the damage proficencie on shotguns.
26. The C4 can be detonated by double tapping the < dpad and also the reload button for the CCP.
27. The FAD has the highest headshot multiplier for the Assault Rifle which is by 1.7x.
28. Due to the fact CoD Elite is not present on the Wii, the Winter and Marine camo are unlocked once you prestige.
29. The riot shield will not cause any bulletholes in the Wii version.
30. The riot shield will only be destroyed in survival mode regardless of platform.
31. The EMP grenade is so powerfull in the Wii that it could destroy ospreys, pavelows and even assault drone within its proximity.
32. If a player is using Assassin Pro while his team is getting their radar jammed or EMP'd, any UAV that he calls will not show up.
33. MW3 is the only Wii Call of Duty tittle that doesnt allow you to knife faster when out of ammo.
34. There is an arcade mission at the edge of the map of Village with the title 'Modern Warfare'. Beside it is a teddy bear
35. There is a Burger Town outlet in Arkaden.
36. Outpost and Carbon is so far the only map in the entire Wii Call of Duty to feature breakable glass other than that of a vehicle's.
37. The Trophy system shoots down its target, let it be pointstreaks or missiles.
38. When equipped on sniper rifles, the thermal scope has a much less magnification that that of the reg. scope.
39. The variable zoom only has 2 magnification in campaign mode unlike 3 in multiplayer
40. When throwing tactical grenades, only half of the riot shield user's body will be covered will be covered.
41. It is possible to have a throwing knife stuck to the riot shield.
42. The FSO, PMC and Inner Circle share the same head model in the Wii version.
42. The USAS 12 and the Skorpion gives you more sprinting time like Extreme Conditioning. Using one of these with extreme conditioning will make you sprint a whole lot longer
43. Smoke grenades works more effective here than in Black Ops's Willy Pete
44. It is highly advisable to use the 44. magnum rather than the Desert Eagle as the magnum does more damage at range. This all depends on the player's opinion.
45. The EMP will make the Javelin useless, regardless if the player has Assassin Pro.
46. You cannot detonate the C4 during an EMP.
47. KSG 12 is the second bullpup shotgun in the entire series, which the first is the HS10
48. IMS can easily be destroyed by shooting it.
49. The Extended Mags attachment will make the shotgun more powerfull by using more pellets in each shot.
50. It is possible to replace your smoke grenade with your own tac. insertion when using the Juggernaut.
51. Despite common belief, the akimbo USP. 45 does not make you lunge despite the animation. It only shows a faster knife lunge animation that works the same as normal knifing.
52. You can still get killed using Blast Shield if the explosion is very near to you.
53. The HAMR and Hybrid scope cannot be used in conjunction with grenade launchers and the under-barrel shotgun.
54. A player using Assassin can still be seen through the thermal scope although harder to spot.
55. Jumping down from a distance can cause damage and if lucky, kill an enemy player or even destroy a car.
56. Do not underestimate the early unlocked shotgun especially the KSG 12. In the right hands it can dominate like the Olympia.
57. Using Akimbo on non-revolver handguns does not increase the total starting ammunition. This means the player only have one spare clip.
58. The AS50 has a lower zoom level compared to other sniper rifles.
59. It is advised to use an automatic or semi-auto shotgun to kill the juggernaut in spec ops survival.
60. When the tactical knife attachment is used on the MP412, the reload animation is shortened as the spinning of the cylinder is not done.
61. During the early development of MW3, Sitrep Pro had the ability to render Dead Silence useless to the user. The feature is not present in-game.
62. SitRep does not mark the airdrop trap red but it does change the package's colour to black with a skull icon.
63. Due to a glitch, equipping the CM901 with any under-barrel will increase its rate of fire.
64. The Dragunov can work similarly to the MK14 given that the ACOG scope is used.
65. The riot shield can block concussion grenades but not flash grenades.
66. Dont try the ACR w/ RDS + Shotgun. The reticle of the red dot is not proper and the bullets will not go where they intended to. (by fissuresofrequent)
67. Dont try to steal your friend's care package. It makes you look like a noob. The only time where they approve packages beng taken is when they use the Escort Airdrop or just leaves the package after seeing it. (by me262)
68. Dont underestimate the Osprey. If you ever try to steal the packages, you will be shot by the osprey as you are standing still.
69. Marine is a Wii exclusive camo obtained when prestiged. The other platforms can only obtain this through other means.
70. It is possible to obtain an assault juggernaut from a care package.
71. The Range attachment increases the 1 shot kill range for ahotguns.
72. The aim assist is much stronger in Spec Ops than in both campaign and multiplayer. Knife lunging is still not present though.
73. All the SMGs kill in 3 bullets in their effective range. Due to the nature of lag, it may take more. (by Pythnator)
74. The Scrambler can hide you from enemy killstreaks, similar to the blind eye perk, given that you're in the radius
75. The Silencer attachment on certain sniper rifles does not affect the damage.
76. The M240 can be obtainable in the mission Goalpost only in the Wii version.
77. In the mission Stronghold, there is a UMP. 45 with the MW2 ACOG scope attached.
78. The G18's ammo capacity in multiplayer is different than it's Campaign variant.