Weapon Types

Each weapon does a particular type of damage, such as Slashing or Bolt. Each weapon type has different strengths and weaknesses against the variety of enemies in the game. These are NOT the same categories as elemental mods: armor piercing, fire, freeze, and electric.

"Normal damage" refers to the Normal column on the Enemy Vulnerabilities page. See that page for weak spots as well.

Ranged Weapons

Bullet

Includes most regular, bullet shooting guns.

Does Normal damage to enemies. Normal damage deals greatly reduced damage against armored enemies, but guns can be aimed at a variety of weak spots for full damage or better.

Bolt

Includes: Bolto, Boltor, Akbolto, and Paris. 

• Ignores all regular damage rules.
• Incapable of Puncture, regardless of mods.
• Almost always does full damage to an enemy's body and double damage to an enemy's head.
• MOA guns take 50% damage. Grineer Commanders and Seekers take Normal (bullet-type) body damage (66%, decreasing more with enemy level) and headshots are double the reduced body damage.
• Ignores weak spots for the base damage calculation, but elemental mods will still be calculated like regular.
• Bolts fired from weapons travel at around 80 meters per second and charged bow attacks travel at around 100 meters per second.

When this damage type kills an enemy, it can throw the corpse backwards and pin it to various objects.  If thrown, dead enemies will deal damage equal to the damage they received, allowing a single bolt to effectively damage multiple enemies.

Beam (details unconfirmed)

Includes only Flux Rifle at this time.

• Does armor ignoring damage to enemies.
• Limited range
• "Continuous Hitscan:" these weapons can be swept across enemies, dealing damage every tick.  In reality, weapons of this type merely tick ten times per second or in other words are just like any other rifle with a fire rate of 10, except that weapons of this type are perfectly accurate and the graphical beam is drawn at all times.
• Similar mechanics to the heat ray of the Fusion MOA .
• An enemy can be biforcated upon death, just like slashing damage.

Elemental

• Snipetron, Kunai, and Despair deal innate armor piercing elemental damage, instead of bullet or bolt. This means its damage will only be less than 100% when used against light infested and MOA gun barrels. Oftentimes does over 100% damage, especially for headshots.
• Lanka deals electrical damage, making it very effective against Corpus, but useless against Infested Ancients.
• Ignis deals fire damage, making it very effective against light Infested.
• Torid and Acrid deal poison damage, which may make them very effective against heavily armored enemies as poison appears to always do 100% damage.  The Torid's grenade may deal normal damage, but this requires testing.
• Ogris and Thunderbolt reportedly deal their own element: explosive.  It is unknown what this does or if this is even true.  Testing is very much required here.
• Dera deals laser damage which is generally slightly inferior to normal damage against enemies, but can headshot Corpus Crewmen.  Laser projectiles travel at around 50 meters per second.

Melee Weapons

Slashing

Includes many bladed weapons not listed in other categories. Ether Daggers are oddly Slashing.

• Normal damage to most enemies
• 3x Normal damage to Infested Walkers and Chargers

Other: Normal damage for the Ancient's Limb weak spots. 2x base damage to crewman head (recheck).

Piercing

Includes Heat Dagger, Dark Dagger, Ceramic Dagger, Fang

• Ignores armor rules and deals damage unmodified by enemy armor/vulnerabilities. Higher level enemies don't get a damage reduction.
• 1.5x damage and charge damage to medium armored Grineer. Other Grineer take regular damage.
• 1/2 damage and charge damage to Infested Walkers and Chargers.

Blunt

Includes Fragor, Furax, Amphis, and Bo.

• Damage is unmodified by enemy vulnerabilities. Almost always does 100%.
• Grineer Commanders and Seekers take Normal body damage (66%, decreasing more with enemy level) and headshots are still 2x body damage. Charge attacks are also reduced the same way.

Notes

• Many newer weapons are unclassified right now.
• Dual Ether are a weird mix of Slashing and Armor ignoring. They can't be classified like other weapons. See their weapon page for more detail.
• Ankyros Ignore Armor. They were updated recently, may be Blunt-type.
• If you hit an enemy's head with melee, you'll deal 2x the damage you would do on a body hit.
• Charge attacks ignore damage-decreasing rules, dealing either 100% damage or more, if the weapon-type gets a bonus against the enemy you're fighting. Daggers are an exception, dealing half damage to Infested Walkers and Chargers and 150% damage to Grineer. The exception to the daggers rule are the Ether Daggers, see the above mention on slashing damage.