Lava

Lava is a Liquid found commonly in large pools once the player has reached a certain depth (about 1200-1500 feet below on the Depth Meter). It will cause a large amount of damage to the player and monsters, and falling into Lava is often fatal unless relevant immunities are in place.

If Water touches Lava, the Lava turns into Obsidian.

Burrowing Monsters and monsters native to the Underworld have an immunity to Lava Damage.

When Lava comes in contact with most placed items, it will burn through them. However, Lava will not burn through regular Wood Blocks and Ice Blocks, and will also not burn through closed Wooden Doors (though as soon as the door is opened it is destroyed).

Lava will destroy all grass, moss, and vines that it comes into contact with. Vines will be destroyed instantly but grass and moss can survive Lava for up to a few seconds. Lava also prevents grass or moss spreading onto blocks near or in contact with lava.

Protection from Lava[]

Lava deals 100 damage to the player (modified by the player's defense), and 50 damage to monsters (modified by the monster's defense). As such, being able to protect oneself from Lava is a high priority when digging deep underground and in The Underworld. There are a few methods of protection available.

Potions[]

The Obsidian Skin Potion grants immunity to Lava for 4 minutes.
The Water Walking Potion allows a player to walk on the surface of a body of lava without taking damage (being inside of lava will still hurt, though).

Accessories[]

A Lava Charm will allow the player to dive into lava for 7 seconds. After that time they will take damage as usual. It is worth noting that if the Lava is shallow enough, that even though it would do damage with the Lava Charm, it will protect you from damage without having a time limit. If you look in the right corner you will see lava symbols just like water bubbles.
As of the 1.2 Update, the Lava Waders are able to be crafted from the Obsidian Water Walking Boots. This accessory allows the player to walk on the surface of Lava as well as to swim in Lava for up to 7 seconds without risk of harm. It is worth noting that when wearing both Lava Waders and a Lava Charm, they will add up to giving 14 seconds of Lava diving without risk.
Flippers will allow the player to swim in Lava (use in combination with other accessories or potions). The Diving Gear is also useful.
While wearing an Obsidian Rose, the player will still take damage, but it will be reduced by 30 after armor and it will reduce the duration on the On Fire! debuff.

Other ways[]

Building a bridge out of blocks over lava will prevent the player (or monsters, or items) from touching the lava, so it also works.

Pouring Water Buckets directly on lava will create a flat surface made of Obsidian. Mining part of the Obsidian will make a void in the lava. This void can be filled with water. A pit lined with obsidian and filled with water allows the player to tunnel through lava. This doesn't work well in the Underworld as water evaporates rather quickly down there.

Lava Traps[]

Lava was thought to incinerate dropped items that are 100% covered by a Lava tile; however, further experimentation has shown the amount is closer to 25%. The optimal way to create a trap is to have 1 bucket of Lava for every 6 to 8 blocks of the trap, this way it still damages the player and creatures without destroying any Coins or loot.

Players and most monsters who are harmed by Lava will always receive the "On fire!" debuff.

Duplicating[]

Main article: Duplication

Build a large pit 1 block deep, and another pit below that pit. Pour a bucket of Lava into the top pit and scoop it back out, then mine a hole to allow the remaining lava into the lower pit. The player can then take that Lava with the bucket.

This procedure can have varying results; sometimes it will work properly and the player may even have Lava left over in the lower pit. Other times it can be less successful, only yielding one duplicated bucket per two normal ones.

Removing[]

Blocks cannot be placed in Lava. However Sand, Ebonsand, Pearlsand, Crimsand, Silt, and Slush can be placed above the Lava, and it will drop to the bottom. A lava pool can be filled in this way. The player can exit the world, re-enter the world, mine the gravity-affected block, and the Lava will be gone.

Notes[]

Any item below tier 1 will be destroyed by any lava pools deeper than approximately one-third of a block, with the exception of Fireblossom, Fireblossom Seeds, and Obsidian. All items of tier 1 and above will be immune to Lava.
Previously, in Multiplayer, when Lava was poured from a bucket, it turned into water for a brief moment, so when you tried to duplicate it, it might actually have produced some Obsidian, but this had to be done quickly. However, this bug has been fixed.

When a world is being generated for the first time, it is possible for a lava pool to be generated over a glowing mushroom spot. In this situation, the large mushrooms and mushroom grass will not be damaged in any way until one of the submerged mushrooms is disturbed by the player, at which point the Lava will destroy all nearby mushrooms and all mushroom grass which is in contact or close to Lava.
If Autopause is on when the inventory is opened, Lava will keep producing bubbles and embers while it's paused.
There is a glitch where if you have an item such as a chest or gravestone placed, water and Lava will touch without making obsidian where they are placed.
Seeing Lava is normally a good indication that the player will soon reach the Underworld if they continue to travel deeper.
Damage from Lava can be dodged by equipping Master Ninja Gear
An Obsidian rose can be used to reduce Lava damage but will not negate it or stop the On Fire! debuff.
When farming Obsidian with natural lava pools, be wary of doodads (decoration details, eg. stalagmites) since when water pours onto a block of Lava with a doodad in it, the water will disappear without forming Obsidian (probably because water hits Lava and the game tells the Lava to turn into obsidian but it can't since the doodad is in the way). This can be used as a (somewhat tedious) method of annihilating water.
Lava can go through half blocks (made by hammering a full block once) to make harmless lava falls just like water and waterfalls.

Trivia[]

The ambient sound files for lava falls (which were added in 1.2.3) also contain very faint sounds of children laughing.^[1] This was likely not intentional, as even Terraria's developers were not aware of the sound.