The Explosives skill determines the ease of disarming any hostile mines and the effectiveness of any explosive weapon (all mines, all grenades, Missile Launcher, Fat Man, etc.)

You will certainly notice the delay you get when it comes to disarming mines, but that’s not a reason to raise a skill, right? No, it’s the fact that Explosives now govern all weapons that… you know… cause explosions? Now it’s a skill worth considering, since Explosives are a wide and often powerful variety of weapons, easily able to overcome the Damage Thresholds of enemies. Of course, it is still a limited-use and often expensive collection of weapons… and certainly not one for use against most enemies. Frankly shooting a Deathclaw with a Sniper Rifle is simpler and more effective than stocking up on heavy and expensive Explosives. In fact Guns and Energy Weapons are more effective and versatile in nearly every combat situation than Explosives, which is why it’s hard to endorse it as an essential skill. If anything it should be one of the last skills you bother to raise.