Dynamite

An explosive-type weapon, dynamite has some traditional applications, as well as offering a means to remove unhelpful NPCs.

Strictly speaking, dynamite is nitroglycerin-soaked charcoal, pressed into sticks. A dynamite package is a collection of a few sticks, taped together, and wired in parallel to a simple timer. This timer can be set for as little as ten seconds of delay, or up to a few minutes.

Applications
In some areas, an explosive like dynamite can be the only way ahead. Dynamite is especially helpful for clearing cave-ins, and can blow most doors apart. However, dynamite can be used as an offensive weapon.

Offensive Strategies
If an NPC follows a set, predictable movement pattern, their timing can be analyzed and a bundle of dynamite set in their path. The timer, set to reach zero just as the NPC reaches that zone in his or her patrol, can potentially kill a wandering NPC. However, a more reliable means of explosive removal exists.

Setting the timer for a minute or two of delay, and then planting the armed dynamite (via pickpocketing) on a character provides a triple benefit: it ensures that the NPC will be as close to the blast as possible, requires no complicated math to properly locate and delay the blast, and allows the player to get well clear before the fireworks begin.

Availability
Dynamite is relatively common, and can be found - or stolen - in many places in the Wasteland. Military facilities often stock dynamite, and mining operations of any type often carry supplies. Dynamite is also a somewhat common item in shops, and can be purchased for reasonable prices with a decent Barter skill. (none in fallout 3)

Applicable Perks
Fallout 2 and Fallout Tactics players disposed to using dynamite, and its more-powerful sibling, plastic explosives, would do well to gain the Demolition Expert perk. With this perk, the player will never have a premature detonation (a common problem with aging timers), and the explosive in question will deal double damage.