SourceEngineDamageTypes
#

https://developer.valvesoftware.com/wiki/Damage_types
DMG_GENERIC = 0

Generic damage.
DMG_CRUSH = 1

Caused by physics interaction. Ignored by airboat drivers.
DMG_BULLET = 2

Bullet damage.
DMG_SLASH = 4

Sharp objects, such as Manhacks or other NPCs attacks.
DMG_BURN = 8

Damage from fire.
DMG_VEHICLE = 16

Hit by a vehicle. This will need to be set for passengers of some vehicle to receive damage.
DMG_FALL = 32

Fall damage.
DMG_BLAST = 64

Explosion damage. Will be ignored by most vehicle passengers.
DMG_CLUB = 128

Crowbar damage.
DMG_SHOCK = 256

Electrical damage, shows smoke at the damage position.
DMG_SONIC = 512

Sonic damage,used by the Gargantua and Houndeye NPCs.
DMG_ENERGYBEAM = 1024

Laser.
DMG_PREVENT_PHYSICS_FORCE = 2048

Prevent a physics force.
DMG_NEVERGIB = 4096

Never creates gibs. Used by the crossbow.
DMG_ALWAYSGIB = 8192

Always create gibs.
DMG_DROWN = 16384

Drown damage.
DMG_PARALYZE = 32768

Same as DMG_POISON.
DMG_NERVEGAS = 65536

Neurotoxin damage.
DMG_POISON = 131072

Poison damage.
DMG_RADIATION = 262144

Radiation. Will be ignored by most vehicle passengers.
DMG_DROWNRECOVER = 524288

Damage applied to the player to restore health after drowning.
DMG_ACID = 1048576

Toxic chemicals or acid burns.
DMG_SLOWBURN = 2097152

In an oven.
DMG_REMOVENORAGDOLL = 4194304

Don't create a ragdoll on death.
DMG_PHYSGUN = 8388608

Damage done by the gravity gun.
DMG_PLASMA = 16777216

Plasma.
DMG_AIRBOAT = 33554432

Airboat gun damage.
DMG_DISSOLVE = 67108864

Forces the entity to dissolve on death. This is what the combine ball uses when it hits a target.
DMG_BLAST_SURFACE = 134217728

This won't hurt the player underwater.
DMG_DIRECT = 268435456

Direct damage to the entity that does not go through any damage value modifications.
DMG_BUCKSHOT = 536870912

The pellets fired from a shotgun.