Grenade Mods (short for Grenade Modification) are useful upgrades that modify the properties of a character's Protean Grenades by increasing their damage, changing their functionality, and/or adding elemental properties. They are named by their elemental property followed by their type, such as "Explosive MIRV" or "Incendiary Rain." Each type of grenade mod is available in a range of different strengths that are roughly proportional to the level of the enemies encountered. Grenade mods are dropped by enemies, found in skag piles and chests, and can be given as mission rewards. They can also be bought as "Item of the day" at Ammo Vendors.
Bouncing Bettie (Dahl) "Bouncing Bettie grenades pop up into the air before exploding."
Contact (Tediore for explosive, Maliwan for elementals) "Contact grenades explode after touching an enemy."
Longbow (Hyperion) "Longbow grenades teleport to their destination and explode."
MIRV (Torgue) "When MIRV Grenades explode they throw out several more grenades."
Proximity Mine (Vladof) "Proximity Mines wait to explode until an enemy gets close."
Rain (Atlas) "Rain Grenades throw themselves into the air and fire down upon unsuspecting enemies."
Rubberized (Pangolin) "Rubberized grenades bounce off all surfaces and explode when they touch an enemy."
Sticky (S&S) "Sticky Grenades attach to surfaces and explode after a few seconds."
Transfusion (Anshin) "Transfusion Grenades steal health from enemies and heal you."
In Borderlands 2, the grenade mod system has been overhauled to include up to seven components in one grenade. The main components are the "payload" (which determines the type of grenade) and the "delivery mechanism". In conjunction with the "elemental accessory" the three form the nomenclature for the grenade in the order of delivery mechanism, element and payload. The four remaining components affect variables of the Grenade Mod such as blast radius, damage and fuse times but don't change the item nomenclature.
Grenade mods in Borderlands 2 use a stat system similar to other weapons. "Damage" indicates the strength of the grenade. "Blast radius" measures the area around the grenade that will be affected. "Fuse time" shows how long it takes for a grenade to detonate after it strikes a surface, in seconds.
Grenade Type (Payload)
Area of Effect (Vladof): Creates a lingering cloud, a column of fire or an electrical field. Cannot be explosive.
Bouncing Bettie (Dahl/Bandit): Fires a hail of bullets while bouncing in one spot.
MIRV (Torgue/Bandit): Releases child grenades after the initial explosion.
Singularity (Hyperion): Implodes to pull in enemies towards it before exploding.
Standard (Tediore): Simple grenade without special effects.
Transfusion (Maliwan): Releases child grenades that steal health from enemies and return it to characters via healing trails.
Grenade Delivery Mechanism
Homing: Flies through the air slowly, but tracks the nearest enemy, navigating obstacles to reach them and after impact falls to the ground.
Homing Sticky: Same as above, but it will stick to the foe it touches. Self-explanatory.
Lobbed: Standard delivery mechanism without special effects. Parabolic trajectory.
Lobbed Sticky: Standard parabolic trajectory and sticks to surfaces and foes.
Longbow: Flies fast in a straight line in the direction aimed until obstructed.
Longbow Sticky: Flies fast in a straight line in the direction aimed until obstructed and sticks to the point of impact.
Rubberized : Bounces constantly until coming into contact with an enemy. Instantly detonates on impact regardless of the fuse time or after a time if it doesn't hit an enemy.