Space Marine 2 Grenades: Frag, Krak, Shock and Melta

The four

Frag. Area damage against light infantry. Its job is the swarm — a Hormagaunt pack, a Cultist cluster, a group of Tzaangors. Cheap, plentiful, and mostly irrelevant once the enemies stop being light. Krak. Armour-piercing, single-target. This is the grenade that matters: it damages Majoris and Terminus targets, and against a Scarab Occult Terminator or a boss it is a real contribution rather than a gesture. Shock. A stun. Its value is not damage, it is the pause — a stunned Majoris cannot complete its attack, which converts a losing exchange into a parry window. Melta Bomb. The heaviest option, for the target that has to die now. Slow to deploy and best used on something that is not moving, which mostly means a boss phase or a stationary Terminus.

Why Krak is the pick above Substantial

From Substantial upward, the fight is decided by Extremis and Terminus enemies rather than by the horde. A Frag does very little to a Zoanthrope pair; a Krak does meaningful damage to the thing that is killing your squad. So the grenade choice is a difficulty-dependent decision, and most players never revisit it. If you are running Ruthless and still carrying Frags, you are carrying a grenade for a problem your primary already solves.

How to actually use them

Grenades do not replace parries. A Krak on a Majoris is not a substitute for the parry-and-execute loop; it is a way to shorten a fight you are already winning or to interrupt one you are losing. Throw before the fight, not during it. The throw animation is a window where you are not blocking, and eating a Majoris combo mid-throw is a common death. Watch the squad. Grenades do not distinguish, and melee classes fight at exactly the range you are throwing into. A Krak into a group containing your Assault player is a self-inflicted casualty.

The capacity question

Grenade capacity is affected by perks and class, so some builds carry more than others. That makes grenades part of build planning rather than a fixed allowance — the perk page covers which perks change it. For the enemies each grenade is for, the enemy list is the reference, and the weapons page covers the primary that should be doing the same job.