Hand Grenade

"Twist the grenade to activate the fuse timer. The longer you hold an active grenade, the farther you’ll throw it. Just remember to throw at some point. Throwing the hand grenade does not make a sound. Therefore the aliens can’t easily trace it back to you."

- The Quake II Manual

Hand Grenades are your average grenade; pull it out, activate it, and throw it. Quake 2's hand grenades can be "cooked" by holding down the fire key for up to four seconds after the grenade has been primed. If you are holding it when the four seconds are up, it'll explode in your hand, usually killing you. To help know when to throw it, a distinct thump sound will be played every second you're cooking the grenade, along with a ticking noise every half-second that indicates an active grenade.

If the grenade hits an enemy, it'll explode on contact. Otherwise, it'll explode four seconds after you've primed it.

Single Player

 * The Hand Grenade is a surprisingly useful Weapon in SP. The amount of damage it does can harm large groups of enemies, and they can kill a Gunner in two blasts.
 * Since enemies will run away from grenades, you'll have to time it so that a grenade explodes in mid-air or as soon as it hits the ground. Try to throw it between the second and third thump for maximum effectiveness.
 * You can also use it as a pseudo-Rocket Launcher by tossing grenades directly at enemies. This is quite useful in the early parts of the game, before you get the Grenade or Rocket Launcher.
 * Hand Grenades can be used for Grenade Jump until player lays hand on Rocket Launcher for propelling and advancing in the air. Hand Grenades don't require players to stand still perfectly for the Grenade Jump unlike Grenade Launcher, as they can be cooked on the run and propel the player up to air with some sense of timing.

Multiplayer

 * In MP, the Hand Grenade is much less effective than in SP. Because of MP's pace, you'll probably get killed while trying to cook a grenade. Leaving a grenade near the entrance to a building, tossing it in a rear hall or elevator shaft can be a useful deterrent for anybody trying to come in while you're running away to grab items, but otherwise don't use it.
 * Also as in SP, Hand Grenades in MP can be used for propelling upwards for reaching important items like any other explosive type weapon.
 * Grenades can be paired with Machine Gun or Shotgun to ambush any heavier weapon carrier around corners. Throwing the first one uncooked then the second toss behind cover mildly cooked would help if foe is at a far distance to corner jump back at them. When they're close up, cooking the first one at your palms for 2 seconds right away then do a ground roll without waiting may help you deny sightlines better for luring them in.
 * Low profile Railgun carriers can be repelled with the use of mildly cooked Hand Grenades. For this technique to be effective player have to have knowledge about arced patterns of trajectory and have a sense of distance for timing. If possible, tossing them in a crouched position would help them to have better accuracy for bombarding porches below them without getting disrupted.
 * Anyone rushing with Chain Gun can be tackled away with smart use of cooked grenades ricocheting from walls forcing them to be at the open and disorient their shooting spree as you take cover. If there's no nearby walls to take a bouncing toss, just throw it on the ground before taking a peek shot at them.