ST-CS-10-339-75
March 2002

10.  HE Grenades  (U)

High explosive grenades are the only area-effect weapon in Counter-Strike. It is useful to be aware of their maximum area of effect and the rate at which damage drops off over distance.

A grenade test map, te_grenade, was created. A central plinth is surrounded by layers of hostages. A grenade is dropped on the plinth, and the health of the hostages is recorded. The map was created in Worldcraft and examining the positions of the hostages gives us their distances from the point of the explosion.

Mass hostage slaughter

After the grenade explosion, each hostage was inspected to find how much damage was caused. We then compare damage to distance and draw the following graph;

The solid line is the damage/distance ratio for hostages, the dashed line is the damage/distance ratio for players.

As can be seen, maximum radius of damage is 350 world units. The basic damage at a range of 0 for hostages (who take more damage from hits than players) is extrapolated to be 170. Damage reduces in linear proportion to range.

The linearity of damage was an unexpected finding; it was thought damage would be non-linear (e.g. realistic) with extreme damage at close range, followed by a rapid drop over distance.

In reality, grenades when they explode generate a given amount of energy. This energy expands outwards, creating a spherical volume. The size of the volume at any given radius is found from the equation "(4/3) times PI times (r to the power 3)" where r is the radius of the sphere.

So at a range of 100 world units, the volume of the sphere is 4,188,790. At a range of 300, the volume is 113,097,335 - twenty seven times larger, which means at a range of 300 the damage inflicted should be one twenty-seventh of the damage at range 100 since the fixed amount of energy created by the grenade is spread out over twenty-seven times the volume by the time the blast radius has spread out to this distance.

Clearly, this is not the case, as the damage at 100 is about 130 and the damage at 300 is about 25.

Unfortunately, all this work turned out to be only half useful, because hostages take more damage than players from HE blasts.

Further experimentation revealed the maximum damage of a HE grenade against a player is in fact exactly 100. It is possible, if the grenade is properly placed at exactly point blank range, to kill an unarmoured player with one blast. Typically, however, the damage inflicted is between 92 and 97 because it's just too hard to get the grenade that perfectly close.

Further testing round that the radius of effect was found to remain at 350 when testing with players. Given the damage at range zero and the maximum range of effect, it was possible to draw the dashed line on the graph which is the damage/distance ratio for players.

Note that armour was found to absorb exactly 50 percent of grenade damage. Grenades are like bullets in that they hit a single particular part of the body when they explode (despite nominally being a blast weapon).

As such, armour may or may not help, depending on where the hit occurs (remember, armour does not protect a player's legs, and a helmet may or may not be present - but will only help if the grenade "hit" struck the headbox).

Grenades are totally unaffected by physical objects in the map. No matter what walls, doors, crates, tanks, reinforced thermonuclear blast proof concrete bunkers (and so on) lie between the target and the point of explosion the damage inflicted will not be reduced in any way.

Over the last two rounds a terrorist had camped to the left of the back door, roughly parallel with the ladder. Throwing a grenade up against the wall next to his position caused exactly the same damage as if the wall had not been there, resulting in the kill.