Grenade

A grenade is a thrown weapon that appears in all of the Fallout games. They contain an explosive payload designed to inflict damage in a wide blast radius. Certain grenade models are more effective against some targets, and less effective against others.

Frag grenade
A Frag Grenade is a timed, hand-thrown explosive which detonates to inflict damage with a concussive blast and a cloud of piercing shrapnel, or 'frags'.

Pulse grenade
Pulse grenades do not explode like frag grenades, but rather emit a pulse of extremely intense electromagnetic radiation. The pulse is only mildly harmful to organics, but is extremely effective at stunning or disabling robotic foes.

Plasma grenade
Plasma grenades, as their name suggests, emit a powerful burst of plasma energy when detonated, as opposed to using chemical explosives like those in a Frag Grenade.

Holy Hand Grenade
The Holy Hand Grenade, also known as Holy Frag Grenade, is a unique weapon in the possession of four or five Power Armor Knights during a special encounter in Fallout 2. This weapon is enormously powerful when compared to a standard Frag Grenade. The encounter cannot be accessed during normal play.

In Fallout: New Vegas, it is found only if the Wild Wasteland trait was chosen, the Holy Frag Grenade is identical in power to the mini-nuke except in hand-held form.

Nuka grenade
A Nuka grenade is a craftable custom weapon in Fallout 3, which exploits the explosive properties of Nuka-Cola Quantum when mixed with some common household chemicals. It does more damage than a standard Frag Grenade, and explodes in a colorful periwinkle fireball.

Bio-gas canister
This grenade does not explode by itself, but instead releases highly-flammable bio-gas vapors upon hitting the ground. The vapors can then be ignited from a distance with an energy or incendiary weapon, causing the leaking gas to erupt in a spectacular fireball. In this way, they function as portable gas-leaks. Added in the Point Lookout add-on.

Cryo grenade
Cryo grenades do only one point of damage, but release frigid Liquid Nitrogen upon detonating, freezing any opponents caught in the blast, and rooting them in place for several seconds. Added in the Mothership Zeta add-on.

Mirelurk bait grenade
Mirelurk bait grenades were to be in Fallout 3, but have since been cut from the game. They would've been used to draw Mirelurks to the point where they detonated. This allowed you to either distract them, or to lure them into a trap.

Smoke grenade
The smoke grenade was planned to be used in Operation: Anchorage, but was cut.

Smoke grenades were also planned for Fallout Tactics, but didn't make the cut either.

Acid grenade
Acid grenades spray a sticky, corrosive substance upon detonation, dissolving anything caught in its blast. They appear to have increased effectiveness against the metal shells of robotic opponents.

Chemical grenade
The chemical grenade was a combination of the acid grenade and the cut smoke grenade. The gas released was designed to be horribly toxic against organic targets.

Tangle grenade
The tangle grenade was designed to be able to ensnare personnel with a tangler polymoid. It was planned to be in Fallout Tactics, but was never added.

Flash grenade
Flash grenades, by themselves, do very little harm. They instead use a magnesium core to release a blinding flash upon detonation, stunning opponents caught in its blast radius.

Incendiary grenade
Incendiary grenades release a blast of burning material on detonation, making it especially effective against fleshy foes. Super-Mutants and Robots are significantly less affected by the blast.

Home-made bomb
A home-made bomb is a crude grenade made out of household chemicals and old pipe-fittings, and typically filled with nails and other scrap for shrapnel. A relatively weak explosive.

Toxic grenade
This grenade does very little damage initially, but releases a cloud of poisonous vapours upon detonation, inflicting Poison Damage over time to anyone caught in its blast.

Mini-nuke grenade
As its name would imply, the mini-nuke grenade is all the power of a Mini Nuke, packed into a hand-held explosive device. Only one exists in the entirety of the game.