Lava

Lava is a light-emitting fluid that causes fire damage, mostly found in the lower reaches of the Overworld and the Nether.

Obtaining
Lava blocks do not exist as items $$, but can be retrieved with a bucket. $$, it may be obtained as an item via glitches (in old versions), add-ons or inventory editing.

Unlike water source blocks, new lava source blocks cannot be created in a space by two or more adjacent source blocks. Lava may be obtained renewably from cauldrons, as pointed dripstone with a lava source above it can slowly fill a cauldron with lava.

Natural generation
During world generation, lava replaces air blocks generated in caves and ravines between Y=-55 and Y=-63. Lava does not replace air blocks inside mineshafts, dungeons, or strongholds.

Lava can also occur as lava rivers from a single spring block, pouring down walls into pools. The spring block can be on the side of a cave, ravine, mineshaft, or stone cliff above ground.

Lava also generates as lava lakes, which can be found above Y=0 within any biome.

Two blocks of lava can also be found in plains, snowy plains, and desert village weaponsmith buildings, or one source in savanna village weaponsmith buildings.

Fifteen blocks of lava can be found in the end portal room of a stronghold: 3 along each side wall, and 9 below the portal frame.

Lava also generates in woodland mansions: two blocks of lava generate in the "blacksmith room", and 25 blocks of lava generate in a secret "lava room".

In the Nether, lava is more common than water in the Overworld. Seas of lava occur, with sea level at y-level 32, about a quarter of the total height of the Nether (as the usable space in the Nether is 128 blocks tall). They can extend down to about y-level 19-22. Lava also randomly appears in single blocks inside netherrack formations. Lava is also generated as a single source in well rooms in nether fortresses. There are also large pockets of lava generated under y-19 and can reach all the way down to bedrock level. These pockets are generally over 12 blocks in height and often connect to a large lava lake on y-32; the size of these pockets in 1.18 can range from the size of a singular pre-1.18 ravine to multiple ravines combined.

Lava generates as delta shapes, which can be found commonly in the basalt deltas biome. Lava also generates in ruined portals and bastion remnants.

Fuel
When used in a furnace, a bucket of lava lasts 1000 seconds (100 items).

Burning


Most entities take damage every half-second while in contact with lava, and are set on fire. An entity/player in lava will also have its remainingFireTicks set to 300, setting it on fire for 15 seconds. This timer is reset to 300 every tick that the victim spends in lava, so it will only start counting down once the victim leaves the lava. Once the victim does exit the lava source, it will burn for just under 15 seconds, taking fire damage 14 times. This is due to the fact that for the first tick outside of lava, its remainingFireTicks decrease to 299, and entities take fire damage when remainingFireTicks is a multiple of 20 and greater than 0. If the victim touches water or rain falls on it, the fire is extinguished, but the lava continues to damage them directly.

In addition, a dense fog effect will be applied for players under lava to obscure vision. This can be slightly mitigated via the Fire Resistance effect.

An entity/player moving in lava has their horizontal movement speed reduced by 50% and their vertical movement speed reduced by 20%.

$$, a player with the Fire Resistance effect or a total Fire Protection of 7 or higher does not catch fire.

Vexes, zoglins, Nether mobs other than piglins and hoglins, the Wither, and players or mobs affected by the Fire Resistance effect are not damaged when touching lava.

The embers or fireballs that fly out of lava are purely decorative and do not cause fires or damage to entities. When rain falls on lava, the black ember particles appear more frequently.

A player in lava lasts a few seconds before dying:

Java Edition

 * 2.5 seconds with no armor
 * 3.5 seconds with full leather armor, no enchantments
 * 4 seconds with full gold armor, no enchantments
 * 4.5 seconds with full chain armor, no enchantments
 * 5.5 seconds with full iron armor, no enchantments
 * 10.5 seconds with full diamond armor, no enchantments
 * 11 seconds with full netherite armor, no enchantments

Bedrock Edition
If the player is wearing armor enchanted with Fire Protection, they can last even longer. With the maximum bonus, the damage is small enough that the natural healing from a full hunger bar can outpace it [JE only], so a player could survive indefinitely as long as they have food and their armor holds up (non-netherite armor is damaged by lava). This maximum bonus can be obtained by wearing 2 pieces of armor with Fire Protection IV and 1 with Protection IV, or 1 piece of armor with Fire Protection IV and 3 with Protection IV.
 * 2.5 seconds with no armor
 * 3.5 seconds with full leather armor, no enchantments
 * 4.5 seconds with full gold armor, no enchantments
 * 5 seconds with full chain armor, no enchantments
 * 6.5 seconds with full iron armor, no enchantments
 * 12.5 seconds with full diamond armor, no enchantments
 * 12.5 seconds with full netherite armor, no enchantments

Fire spread
Lava can cause fires by turning air blocks to fire blocks:


 * in a 3×1×3 area right above the lava.
 * in a 5×1×5 2 blocks above the lava.

In order for air above lava to turn to fire, a block adjacent to the air has to be flammable, or one of the wood-constructed non-flammable blocks. Since catching fire depends on air blocks, even torches or lava itself can prevent a flammable block from catching fire. Additionally, not all flammable or wood-constructed blocks can be ignited by lava.

The lava of any depth can start fires this way, whether or not it appears to have a current.

Note that an air block in the 5x1x5 area catches fire regardless of what is directly or diagonally below it. In particular, a single layer of obsidian on the surface of a lava lake does not prevent the blocks on top of it from catching fire from the underneath lava.

Flow
Lava flows from "source blocks". Most streams or "lava-falls" come from a single source block, but lava lakes (including the "flood lava" in the bottom 10 layers) are composed entirely of source blocks. A source block can be captured only with a bucket.

In the Overworld and the End, lava travels 3 blocks in any horizontal direction from a source block. Lava flows far more slowly than water (1 block every 30 game ticks, or 1.5 seconds), and sourceless lava flows linger for a short time more. In the Nether, lava travels 7 blocks horizontally and spreads 1 block every 10 game ticks, or 2 blocks per second, which is half the speed as water in the Overworld. In all dimensions, lava spreading uses the same mechanic as water: for every adjacent block it can flow into it tries to find a way down that is reachable in four or fewer blocks from the block it wants to flow to. When found, the flow weight for that direction is set to the shortest path distance to the way down. (This can result in lava flows turning toward dropoffs that they cannot reach in the Overworld and the End.)

Flowing lava destroys the following in its path: saplings, cobweb, tall grass, dead bush, wheat, flowers, mushrooms, snow on ground (but snow blocks are immune), lily pads, vines, levers, buttons, all three types of torches, redstone, repeaters, end rods, and rails. Sugar canes hold back lava, but disappear if the sugar cane's water source is destroyed by the lava. Lava also slows down entities, including those that are normally immune to lava damage.

Using redstone wire, a one-block lava flow can be redirected by supplying power to the source block, which causes it to reset the flow toward the now-nearest terrain depression. It cannot, however, be reversed. This re-calculation is made because of the redstone wire when toggled changes the block from redstone (on) to redstone (off). Whenever a block updates on any side of the lava, the lava re-calculates where to flow, but does not cut off its current direction of flow. In Bedrock Edition using the /setblock command can be used to create stationary lava without the use of barriers.

Flowing lava can push entities.

Lava and water
Water and lava can produce stone, cobblestone, or obsidian based on how they interact. Lava can also generate basalt when above soul soil and touching blue ice.

Light source
Lava blocks emit a light level of 15.

Other


Lava above a non-transparent block (does not include stairs, fences, and slabs) produces dripping particles on the underside of that block. These droplets do not do anything other than warn the player that a deluge of lava lies above that block. The particles function identically to their water counterparts, except that they drip slower.

Flowing lava can set off tripwires because it breaks placed string. Lava triggers a tripwire only once.

Any item dropped onto a lava source block is immediately destroyed, except for items made of netherite, as well as ancient debris and netherite scrap.

Lava can be placed in an empty cauldron.

If lava is above a non-transparent block supporting pointed dripstone, dripping particles are created on the end. These can fill cauldrons with lava.

Farming
Lava farms can be created by placing a lava source block on top of a solid block and a pointed dripstone and a cauldron underneath.

ID




Lava spends most of its time as stationary, rather than 'flowing' – regardless of its level, or whether it contains a current downward or to the side. When specifically triggered by a block update, lava changes to 'flowing', update its level, then change back to stationary. Lava springs are generated as flowing, and lava lakes are generated as stationary.

Trivia

 * A player with Fire Resistance can swim in lava without taking damage, although the swimming speed does not become faster.
 * A player cannot sprint-swim in lava.
 * An arrow catches fire when shot into flowing lava, but not still lava.
 * Water flows into lava-occupied blocks as though it were empty space, and vice versa.
 * Although lava is a fluid, it is not possible to drown in lava. This applies to all mobs. However, it is still possible to suffocate in lava. This applies to almost every mob.
 * A player sleeping in a bed cannot be damaged by lava.
 * If the lava is changed to be transparent via a resource pack, it does not become transparent.
 * $$, lava does not deactivate elytra like water does.
 * Despite flowing identically to water while in the Nether, it is still not possible to create an infinite spring of lava.
 * Despite this, the Minecraft: Combat Handbook (2014) stated the possibility to create infinite sources of lava by simply creating a cross shape with 4 nether bricks and placing lava in the middle. As expected, this turned out to be false, as confirmed by Dinnerbone.
 * Geologically, lava in the Overworld is consistent with felsic lava, and lava in the Nether is consistent with mafic lava. Felsic lava is slow, sticky, and does not run as far as mafic lava, which is relatively thin and runny.