Explosion

An explosion is a physical event, generally destructive, that occurs in several different circumstances. It can destroy nearby blocks, propel and damage nearby entities, and cause fires in some cases. Explosions produce a "shockwave" particle effect. Explosives include ghast fireballs, TNT, End crystals, beds when used outside of the Overworld, and respawn anchors when used outside of the Nether.

The propulsion effect of explosions is often used for TNT cannons.

Each affected entity is accelerated by between 0 and 1 blocks per game tick (0 to 20 blocks per second), added to its current velocity. This effect can accumulate over multiple explosions, even within a single tick.

In Java Edition, the magnitude of the velocity given to each entity in the range of an explosion is calculated with the following code:

magnitude=(1-distance/(2*power))*exposure*knockbackMultiplier*(1-EXPLOSION_KNOCKBACK_RESISTANCE)

Or in formula form, .

In Bedrock Edition, the magnitude of the velocity given to each entity in the range of an explosion is calculated with the following code:

magnitude=(1-(distance-width/2)/(2*power))*exposure*knockbackMultiplier

Distance is measured from the explosion center to the entity's feet position. Width is the width of the affected entity's collision box. A list of explosion powers can be found in the Causes section. Exposure is discussed in the Exposure section. Explosion knockback resistance refers to the attribute explosion_knockback_resistance. The knockback multiplier depends on the cause:

To calculate the final velocity, the game takes the vector pointing from the explosion center to the entity's eye position ‌^{[Java Edition only]} / head position ‌^{[Bedrock Edition only]} and sets its length to the previously calculated magnitude. TNT entities are the only exception, where the direction goes to the tnt's feet instead of its eyes ^{[verify for Bedrock Edition]}.

The following code is used to calculate the damage inflicted on an entity:

impact=(1-distance/(2*power))*exposure;
damage=(float)((impact*impact+impact)/2*7*(2*power)+1)

In formula form, this is:

.

Players are damaged differently depending on difficulty. The main damage value is used to calculate the final damage in other difficulties:

At the end of each game tick only the highest single explosion damage is chosen. Note that the main damage value has a +1 at the end, so all entities in range (within ) of an explosion receive at least 1 damage even when the explosion is fully blocked. The only exceptions are invulnerable entities, Nether stars, and Peaceful players.

The Blast Protection enchantment and the Resistance effect are handled separately.

The exposure is a measurement of how much of the explosion is blocked by blocks. It ranges from 0 (when the explosion is entirely blocked) to 1 (when there are no obstructions).

To calculate the exposure, the game picks a set of sample points in the entity and casts rays from the explosion center to each point.

For each ray, the game checks if it intersects with any block hitbox. If it does, it is considered obstructed. The exposure is then calculated by dividing the number of unobstructed rays by the total number of rays.

The sample points are arranged in a 3D grid. , , and represent the X, Y, and Z dimension of the entity's bounding box respectively (measured in blocks).

Points on the grid are spaced by

With the negative corner at

• Exposure is directionally biased (and the ray targets can sometimes be outside the entity) due to bug MC-232355. This mostly affects small entities and entities that are far from a multiple of 0.5 wide.
• The top of scaffolding only obstructs exposure rays if the feet position of the affected entity is above it. This has the effect of explosions appearing to travel down through scaffolding but not up.
• For blocks whose collision box extends outside the full cube containing them (walls, fences, the back of piston arms, moving blocks, etc.), they only obstruct exposure rays if the rays intersect the full cube where the block is located.

On a small scale, explosions form a roughly spherical crater. The size of that crater is dependent on the power of the explosion and the blast resistance of the destroyed blocks.

To calculate the blocks affected, "rays" are created from the explosion center to the outer points of a 16 by 16 by 16 grid. Each of those rays gets an intensity of .

For each ray, with the position starting at the explosion center:

1. The game checks the block at the current position (this ignores block shape).
2. If the block isn't air, intensity is reduced by .
3. If the remaining intensity is above 0 and the block can be blown up, it gets added to the list of blocks to blow up.
4. Position is moved 0.3 blocks along the ray.
5. Intensity is reduced by 0.22500001.
6. If the remaining intensity is above 0, repeat from step 1. Otherwise, continue with the next ray.

This typically results in the maximum sphere of block damage having a radius of approximately 4/3 times the explosion power. This can be experimentally verified by repeating an explosion of a set explosion power at some coordinate inside blocks and measuring the radius of the resulting sphere of air.

After the process is done, the list of blocks to blow up is shuffled. For explosions that can cause fires, the game attempts to generate fire in ¹⁄₃ of the blocks in the list. This fire is successfully placed only when above an opaque block.

Due to the fact that the game ignores block shapes when checking blast resistance, explosions happening inside a non-full block get dampened heavily. Sufficiently weak explosions happening on ender chests, enchanting tables, or any height of water or lava don't do block damage.

Blocks destroyed by explosions have a chance to drop items as if mined with an unenchanted diamond tool. Blocks destroyed by TNT have a 100% chance of dropping. Other explosions have a ¹⁄_power chance of dropping items. However, dragon eggs, beacons, conduits, heads, shulker boxes and decorated pots^[1] always drop from explosions.

The drop chance of blocks in explosions can be customized via three game rules: blockExplosionDropDecay‌^{[JE only]} (includes End crystals), mobExplosionDropDecay‌^{[JE only]} and tntExplosionDropDecay. Only tntExplosionDropDecay is set to false by default. If an explosion's drop decay is set to false, items have a 100% chance of dropping.

Worlds created before 1.21 retain their old tntExplosionDropDecay settings. Upgraded worlds need to use /gamerule tntExplosionDropDecay false to get the new behavior.‌^{[BE only][2]}

Despite doing damage to entities, fireworks do not destroy terrain and as such are not counted as conventional explosions.

Lab tables sometimes perform a non-terrain-damaging explosion when creating garbage item.‌^{[BE & edu only]}

The following table shows the blast resistance values used in Minecraft's code for all blocks. In add-on documentation for Bedrock Edition, these values are multiplied by 5 when used for the explosion_resistance value in the minecraft:destructible_by_explosion component. For example, cobblestone has a blast resistance of 6, so to make a custom block with the same blast resistance as cobblestone, quintuple that (which is 30) must be stored in its explosion_resistance value.

[edit values]

Java Edition

Bedrock Edition:

Issues relating to "Explosion" are maintained on the bug tracker. Issues should be reported and viewed there.

• Explosions with a power greater than 100 look mostly the same from the outside, as only certain lines are used to determine if a block breaks. However, some of those lines continue underground.
• Explosions that occur in flowing water or lava apply propulsion and damage to entities, but don't affect any blocks, regardless of the blocks' blast resistance.
• Underwater explosions don't emit smoke particles.
• Explosions can redirect projectiles, including ender pearls.
• An explosion just after a mob's death can propel the mob's body.
• If a falling sand entity falls into primed TNT when in water, it deals block damage.