Semtex

The Semtex is a type of grenade that sticks to the first surface it touches including other players, as seen in the Call of Duty: Modern Warfare 2 multiplayer trailer.

Real-life use
The Semtex was first developed by Czechoslovakia in the 1950s, and was similar to C4 except it could withstand more heat without reacting. It saw widespread use, especially by Libya, North Vietnam and Northern Ireland. Now, because of government restrictions, most of the 10-ton annual production of Semtex is exclusively domestic. Semtex was similar to other plastic explosives, especially C-4, in that it was easily malleable; but it was usable over a greater temperature range than other plastic explosives. There are also visual differences: whereas C-4 is off-white in colour, Semtex is brick-orange.

In-game appearance
The first in-game use of Semtex was seen during the Call of Duty: Modern Warfare 2 multiplayer trailer, working like a regular grenade and having the same principles as the Call of Duty: World at War Sticky Grenade. Its appearance is unusual for a grenade; it is a plastic explosive that has been balled up around a timed detonator with a flashing light.

It appears in multiplayer as well as the Special Ops levels Body Count and Wreckage.

Multiplayer
Semtex takes up the equipment slot. It is obviously comparable to the standard grenade, but with some differences. It cannot be cooked, which limits its direct killing power as the delay gives the opponent time to escape. Additionally, it has a big blinking red light and beeps softly, making it easier to spot and avoid. However, despite its inability to kill directly, it is often more useful than a grenade at flushing an enemy out of a hiding spot, making it possible to kill them with guns. Because the grenade sticks to the first surface it touches (except glass, which it shatters while having its trajectory remain unaffected), it will not bounce and roll past the desired target. This is very useful for sticking the grenade to the Headquarters. Additionally, it can be stuck to the window sill in front of an enemy rather than actually requiring the grenade go through the window (a throw which, if missed, often means a cooked grenade comes bouncing back at the thrower.) Additionally, Semtex grenades cannot be thrown back at the original sender.

Due to its stickiness, it is very useful for taking down riot shields, which it attaches itself to. If the shield user has Blast Shield he/she may survive even a direct stick to the shield.

Trivia

 * If you mistakenly pull out your Semtex you can press your "weapon swap" button, and it will return to your inventory, and not explode.
 * It is odd, since in real life, Semtex is a replacement for C4, however, if you stick it to a wall right in front of you, there is a "C4" label on it, which can also be seen in the multiplayer menu and the art book which comes with the Hardened Edition
 * It is also odd how the semtex grenade can be used after an EMP is used since it appears to be detonated electronicly.
 * Semtex can be used in Spec Ops missions to destroy armoured vehicles like the BTR.