Explosives

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

$$\text{Initial level}=2+(2\times\text{Perception})+\left\lceil\frac{\text{Luck}}{2}\right\rceil$$

Example: A starting Perception of 5 and Luck of 5.

$$2+(2\times5)+\left\lceil\frac{5}{2}\right\rceil=15$$

Fallout 3
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 perk.

This skill does not apply to missiles or mini nukes; these use the Big Guns skill instead. Explosives also does not apply to the act of pants-exploding—using Sneak to successfully plant a live explosive onto an NPC.

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. Grenades may also be used to rearm a formerly rigged Terminal. While using V.A.T.S., grenades explode on contact with a target. Don't forget that you can hold down the attack button to charge the throw of a grenade.

Hostile mines and grenade traps may also be disarmed. Read below for the required skill to disarm them.

Explosives in quests and exploration
Your Explosives skill determines how close you can get to mines before they detect you, as well as how long the mine will take before it explodes. There does not appear to be a minimum Explosives skill necessary to disarm a mine, so long as you can run up and activate it fast enough. But if you're slow or your skill is too low, it will blow before you can do that.

Specific levels of Explosives are required to disarm certain explosive-based traps. Note: 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 Grenade Bouquets
 * 45 is required to disarm Rigged Computer Terminals
 * 50 Explosives is required to train the residents of Big Town in placing a minefield during Big Trouble in Big Town.
 * 60 is required to disarm Rigged Baby Carriages
 * High explosives can cause Reilly to reveal that her rangers left mines to slow down the mutants during the Reilly's Rangers quest.
 * 65 is required with 65 Science to have a statistically good chance of disarming a slave collar.

Ways to increase Explosives

 * Bobblehead - Explosives (permanent +10)
 * Little Leaguer (permanent +5 for each rank)
 * Duck and Cover! (permanent +1 or +2 with Comprehension)
 * Tag! (permanent +15)
 * Raider blastmaster helmet (temporary +5)
 * Torcher's Mask (temporary +5)
 * Takoma Park Little Leaguer Cap (temporary +5)
 * Bombshell Armor (temporary +10, requires The Pitt)
 * Mentats (temporary +2-10 depending on perception, a perfect perception of 10 will see no benefit)

Fallout 3 Explosive Weapons
See Fallout 3 weapons.

Fallout: New Vegas
In Fallout: New Vegas, many more types of weapons fall into the explosives category. Any weapon that was a big gun in Fallout 3 and made an explosion (such as the Fat Man) was moved to this category when Big Guns was removed, meaning the skill is a lot more useful. The rough calculation of damage is 2 points in the explosives skill equals +1 damage (e.g. +20 from Patriot's Cookbook adds +10 damage from 80>100).

Explosives in quests and exploration

 * 25 Explosives to convince Easy Pete that you need a donation of dynamite in Ghost Town Gunfight.
 * 35 Explosives to disarm the bomb in the monorail train at Camp McCarran.
 * 40 Explosives to tell Pete, a child Boomer, something that will get you boomer fame.
 * 45 Explosives to completely train the Misfits in the use of grenades (25 to give an incomplete instruction).
 * 50 Explosives to free the Weathers in Left My Heart without the key (Or 35 to kill them).
 * 50 Explosives to blow up both the sulphur deposits under Vault 19 and the entire vault.
 * 50 Explosives to rig President Kimball's vertibird to explode in Arizona Killer.
 * 50 Explosives to defuse the bomb onboard the President's Vertibird in You'll Know It When It Happens.
 * 50 Explosives to help Caesar's Legion learn to disarm NCR mines.
 * 60 Explosives to blow up the sulphur deposit under Vault 19 without blowing up the vault.
 * 75 Explosives to threaten Father Elijah with blowing up the Sierra Madre Vault.

Ways to increase Explosives

 * Duck and Cover! (permanent +3 or 4 with the Comprehension)
 * Tag! (permanent +15)
 * Patriot's Cookbook (temporary +10 or 20 with Comprehension)
 * Absinthe (temporary +6 (100 Survival), Perception 10 will see no benefit 8-9 will see reduced benefit)
 * Raider Blastmaster Helmet (+5 when worn)

Fallout: New Vegas Explosive weapons and mods

 * See Explosive weapons
 * See Explosive weapon mods

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.