# Is a Creeper's blast radius affected by the surrounding material?

In Minecraft, I would like to build my house out of Glass for aesthetics, but I'm worried it will be very vulnerable to Creepers. In order to minimize potential damage, I'm thinking of building my ground floor out of cobblestone. However, I'm not even sure if this will make a difference, seeing as I don't know whether or not a Creeper's explosion is smaller/larger depending on whether it's exploding against open air, dirt, stone, etc.

It seems that it explodes in a larger radius in a bunch of earth than in a bunch of stone, but I'm only going off of subjective (albeit painful) experience here. Can anyone enlighten me?

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Volcanic rock (the hard black stuff you get when you mix lava and water) is supposed to be impervious to creeper explosions. – Keaanu Oct 3 '10 at 23:11
@Keaanu Obsidian? – Kevin Yap Oct 3 '10 at 23:15
@Kevin yeah, that's the stuff – Keaanu Oct 5 '10 at 0:13

The Minecraft Wiki article was updated with even more in-depth information on explosions:

Steps for calculating what blocks get destroyed:

• Start linearly in the direction from the explosion point to each of 1352 points that uniformly distributed on the surface of a cube centered at the explosion with an edge length of 2.
• Let blast force on each line equal the `explosion power multiplied by a random number in [0.7, 1.3]`.
• Check current block every step of 0.3. A non-air block absorbs `(blockResistance / 5 + 0.3) * step of the blast force`; if the blast force is not completely absorbed, the block is destroyed (air blocks can also be marked as destroyed).
• The blast force is attenuated by `step * 0.75` each step, if the blast force is completely absorbed or attenuated, perform the same process on the next line.

The maximum travel distance in the air of a TNT explosion is 6.9, 5.1 for a Creeper explosion, and 1.5 for a fireball explosion. For example, a TNT explosion can destroy a torch 7 blocks away. The minimum block resistance required to absorb maximum blast force of TNT explosion (with at least attenuation of 2 steps) is 77.67, 63.5 of Creeper explosion, 20.17 of fireball explosion. So water, stationary lava, obsidian, and bedrock are always indestructible, and furnaces and less resistant blocks can be destroyed by fireballs.

There's also a list of every block in the game with it's explosion resistance, but it would probably look horrible copy and posted in this answer.

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(I hope I understood your question correctly.) – Kevin Yap Oct 4 '10 at 2:14
This is definitely the type of information I was looking for! There's a line that was recently added to the Creeper article on 9/4/10 which states that their explosions don't currently effect hard materials, which confused me. However, given my and others' experience, this seems to be false. – FAE Oct 4 '10 at 17:37
Do explosions go THRU materials? For instance, if I completely surround a piece of glass with obsidian, then surround that with TNT and detonate it, will the piece of glass break? – BlueRaja - Danny Pflughoeft Oct 5 '10 at 20:00
Hmm, I'm not sure about that. I would assume no, but I'd have to test it to be completely sure. – Kevin Yap Oct 6 '10 at 0:46
@FallenAngelEyes The article says that happens in Survival Mode; under the InDev / Infdev / Alpha part of that section, it says "Unlike in Survival mode, the explosion caused by a creeper in Indev mode can destroy stone and other hard materials but the harder the material, the less effective the explosion.". – Kevin Yap Oct 10 '10 at 20:07