From Dungeons of Dredmor Wiki

The Anvil of Krong is an altar found in the dungeons.

Placing any wearable item (including not just armor but also weapons) on the anvil will result in it gaining an enchantment (and becoming an artifact). There is a 5/7 chance of it gaining a positive enchantment, and a 2/7 chance of it gaining a negative enchantment. This does not apply to the character's first use of an Anvil of Krong, which will never result in a curse. If it gains a positive enchantment, the item will acquire 1-2 points worth of bonus stats (and sometimes 1 or more additional bonus points of boosts to your primary attributes, due to a bug). For a negative enchantment, the item will acquire 2-4 points worth of penalty stats (and again a possibility for additional points if they are modifiers to the primary attributes).

Non-random artifacts (such as the Poncho With No Name) will not gain a random name when upgraded. If a positive enchantment is selected, non-random artifacts will also gain a different amount of enchantments, equal to their Artifact Quality.

Note: Certain non-random items are considered "artifacts", but do not have an Artifact Quality value. These items will not gain a positive enchantment even if they are used on the anvil. It is unclear whether this is an intended game mechanic.

You can also place bolts or throwing items onto an Anvil of Krong to turn them into artifact items. Damage bonuses gained this way will affect the damage caused by these items, but no other bonus or negative attribute will affect your character as you cannot wear these items.

• If an artifact bolt or throwing item is placed into a crafting container, it will lose its artifact status. Ammo recovery from artifact bolts or throwing items will give you a normal item of the same type. Any normal item of the same type as an artifact bolt or throwing item can be placed on the artifact stack, allowing you to increase the size of the artifact stack. Placing the artifact stack onto a stack of normal items of the same type will result in a stack of normal items, thus wasting the Krong.

Archaeologists can recharge an anvil with the spell Ancient Kronian Ritual, but only once per anvil.

Occasionally an Anvil of Krong will be found corrupted. Killing all the monsters in the room appears to cleanse the anvil, restoring it to an unused state. An Archaeologist can still use the Ancient Kronian Ritual on it, as usual.

[edit] Special Weapon Enchantments

Spell Name	Description	Notes
Boot	...boots your enemies away from you.	Knocks monster back.
Electrical Strike	...shocks your enemies with bolts of electrical energy.	Damage: 2 + ( 4 + 0.2 ) with 33% chance to paralyze for 1 turn.
Arctic Cold	...freezes the flesh of your enemies.	Damage: ( 3 + 0.3 )
Ignition Bolt	...sets your enemies on fire.	Damage: 1 and burns the target.
Pyrokinesis	...sets your enemies aflame.	Sets a single monster on fire and deals ( 3 + 0.75 ) once. Additionally causes Fire 1.
Fleshbore	...bores into the flesh of your enemies.	Damage: ( 2 + 0.21 ) for 4 turns and debuffs -2 -1 -3 -1 -1 -1
Thaumite Infection	...infects your enemies with ravenous thaumites.	Damage: ( 3 + 0.18 ) and then 7 turns of ( 4 + 0.21 ) for every turn and debuffs -10 -2, revokes itself to the ground after the 8th turn for 32 turns.
Midas	...transforms the flesh of your enemies into gold.	Damage: 4 +0.15 & Midas (Effect)
Mini Curse	...curses your enemies with weakness.	Damage: ( 4 + 0.4 ) and debuffs -1 -1 -1 -1 for 10 turns, Stacks 10 times.
Sleep	...puts your enemies to sleep.	Damage: ( 1 + 0.1 ) and sleep on target.
Nightmare	...sends your enemies into a terrible nightmare.	Damage: ( 3 + 0.15 ) and sleep on target.
Force Blast	...blasts away everything in front of you.	3x3 AoE around the player. Damage: ( 2 + 0.15 ) and 100% chance to paralyze for 1 turn, knocks monsters back by 3 tiles.
Blinding Flash	...blinds everyone around you with burning light.	Damage: ( 2 + 0.32 ) + ( 2 + 0.23 ) and 33% chance to paralyze for 5 turns.
Rockburst	...pounds your enemies with rocks.	Damage: 8 5 5
Dragon's Breath	...shoots of burst of flame toward your enemies.	Shoots a 5 flame that travels three spaces forward, then bursts into a 3x3 AoE flame lasting 3 turns.
Root	...roots your enemies to the ground.	5 turns of lockdown and debuffs -8
Blast Effect	...gives you mighty powers of blasting.	Damage: 1
Fire	...starts a fire under your enemies.	Lasts 20 turns on the ground. Damage: 8 and burn the target walking on it.
Acid Burn	...burns your enemies with acid.	Lasts 5 turns. Damage: 6 and 2 for every turn and debuffs -4 -1 -1 -1. Additionally causes bleeding.
Vampirism Attack	...allows you to sap the life of your enemies.	Damage: ( 2 + 0.14 ) and heals the character for (damage done by this skill + 1).