Explosives

Explosives is a Fallout 3 skill, replacing the Traps and Throwing skills from previous games. Its governing primary statistic is Perception.

Uses
The Explosives skill governs all mines and grenades. The higher your skill, the higher the damage you inflict. A minimum skill level is also required to unlock the Demolition Expert and Pyromaniac perk.

This skill does not apply to Missiles or Mini Nukes; use Big Guns instead. Explosives also does not apply to the act of pants-exploding--use Sneak to successfully plant a nasty surprise.

Use Explosives to set Frag Mines, Pulse Mines, Plasma Mines, or Bottlecap Mines. They all explode by proximity, not by contact. Mines may be placed anywhere, including tables and ledges to bring the area of effect closer to the head or torso. You may also reverse-pickpocket mines into an NPCs inventory.

In Fallout 3 the Explosives skills affects the distance and accuracy of a thrown bomb: including the Frag Grenade, Pulse Grenade, Plasma Grenade and Nuka Grenade. The player cannot set grenade traps like mines, though they can be planted on a hapless victim. Grenades may also be used to rearm a formerly rigged Terminal. In Vats, grenades explode on contact with a target.

Hostile mines and grenade traps may also be disarmed.

Disarming
Your Explosives skill determines how close you can get to mines before they detect you, as well as how long the mine will beep a warning before it goes off. There does not appear to be a minimum Explosives skill necessary to disarm a mine, so long as you can run up and click on it fast enough. But if you're slow and your skill too low, it will blow.

Specific levels of Explosives are required to disarm certain explosive-based traps. The Repair skill is used to disarm any trip wires or pressure plates associated with traps.
 * 25 is required to disarm Megaton's atom bomb.
 * 30 is required to disarm hanging Frag Grenade clusters
 * 45 is required to disarm Rigged Computer Terminals
 * 60 is required to disarm exploding baby carriages

Increasing Explosives skill
Explosives can be increased by wearing Raider Blastmaster Helmet and Takoma Park Little Leaguer Cap, as well as any armor/clothing that increases PE such as Crow's Eyebot Helmet.

Explosives in Quests

 * 25 Explosives is required to interact with Megaton's atomic bomb.
 * It is also required to have a high enough Explosives skills to disarm any Slave Collars on slaves.

Previous games
In Fallout, Fallout 2 and Fallout Tactics, the character’s ability to throw a grenade is directly related to the Throwing skill. The character’s ability to set or disarm an explosive is related to the Traps skill.