In multiplayer, the Ballistic Knife is unlocked at level 15 and the Crossbow at level 33, and they cost 1500 each. Both weapons have no attachments available, but kill instantly if the shot lands on target, though with the Crossbow the player has to wait for the bolt to explode after hitting the target (unless playing in hardcore modes). They also have full mobility, so they do not negatively affect the player's speed.
As for the Death Machine, the Grim Reaper and the Valkyrie Rockets, they are not selectable from the Create-a-class menu, but can be obtained via Care Packages killstreak rewards.
In Zombies, both the Ballistic Knife and the Crossbow are available through Mystery Box, while the Death Machine is obtained as a Power-Up. When Pack-a-Punched, the upgraded Crossbow functions similarly to a Monkey Bomb, distracting zombies to where the arrow lands, and the upgraded Ballistic Knife can revive downed teammates if the player shoots at one (doing this for the first time awards the player with the achievement/trophy See Me, Stab Me, Heal Me). Each Special Weapon can only be obtained by one person at a time in a single game (aside from the Death Machine if the Kassimir Mechanism easter egg or the Cryogenic Slumber Party are completed).
Specials return in Call of Duty: Black Ops II. Many are unique to campaign mode, where they can be equipped on their custom loadout. Some are unlocked upon completion of a level, while others are unlocked upon the completion of several challenges. The Valkyrie Launcher, however, is not usable in loadout. Some, like the Spring Knife, Manual Crossbow, and Minigun, are based on weapons from Black Ops, being similar to the Ballistic Knife, Crossbow, and Death Machine respectively from the game. Future versions of these weapons are also available. The Assault Shield is a new Special which acts similar to the Riot Shield in Modern Warfare 3, except for the the fact that the player is able to plant it on the ground and use it as defense.
Specials are available in multiplayer. The Combat Knife is a replacement to the standard knife from previous games, and will take the slot of a weapon if one is chosen to not be equipped. The Assault Shield also appears in multiplayer as a primary weapon, unlike specials in Black Ops. The future variants of the Ballistic Knife and Crossbow also appear as secondary weapons. Like all secondaries, they are able to have camouflage equipped. The Death Machine and War Machine however are Scorestreaks.
The Ballistic Knife reappears in every map except for Mob of the Dead and Origins. In Zombies, it uses the Black Ops model, and is still able to revive players when it is Pack-a-Punched. The War Machine also appears in all maps except Mob of the Dead, but unlike its multiplayer counterpart, it shoots grenades which bounce and explode after a set time. The Death Machine is exclusive to Mob of the Dead. A zombies version of the Assault Shield, the Zombie Shield appears in TranZit, Mob of the Dead, and Origins as a buildable, and has a different model on each map.
Specials appear in multiplayer, with the Riot Shield and Combat Knife being the only ones available for Create-a-Soldier. The MAAWS launcher is a pointstreak, and Minigun is used with the Juggernaut pointstreak. The Venom-X appears as an Easter Egg in the Devastation DLC on the map Unearthed. The latter two weapons can be received from an Ammo Crate as well.
The Heavy Shield, the MDL and the M1 Irons appear as primary weapons, whereas the Crossbow appears as a secondary weapon. The Combat Knife is equipped if the player removes their primary or secondary weapon, or when they crouch or go prone in a swimming pool.
If the Remote Turret scorestreak is equipped with the Rippable module, the turret can be ripped off and carried. The default configuration is the MG, while the Rocket and Directed Energy variants are available via additional modules.
The MDL is available in Exo Survival, though it is bought from the Launchers selection. The Combat Knife is only used when crouching or going prone in a swimming pool. Additionally, the ripped MG, Rocket and Energy turrets can be obtained in the same way as in multiplayer.
The Crossbow, M1 Irons, LZ-52 Limbo and KL03-Trident can be obtained from the 3D Printer. The Combat Knife is once again only equipped when going underwater, and the three ripped turrets are available; all turrets automatically come with this Rippable module in Exo Zombies.
The Spike Launcher, Micro-Missile Launcher and Death Machine are available in the campaign. They cannot be selected in the custom classes, but can be found in some missions. Additionally, instead of occupying the two main weapon slots, they are selected from the D-Pad for the equipment slot (like with the launchers and the Sheiva SSW).