Minecraft bedrock locator: find a position from the pattern
Bedrock at the bottom of the Minecraft world is not random: its pattern is generated deterministically from the seed and the coordinates. Mark a bedrock pattern on the grid, learn the location technique and use external tools to calculate the exact X/Z coordinates.
How locating by bedrock pattern works
Mark the bedrock pattern
Technical details of bedrock generation
In Minecraft Java Edition, bedrock at the bottom of the world (Overworld: Y=0 to Y=4, Nether: floor and ceiling) is generated by a deterministic pseudo-random algorithm. For every block (X, Y, Z) the game works out whether bedrock should be there, using these rules:
- Y=0: Always bedrock (100%). This is the "floor" of the world.
- Y=1: ~80% chance of bedrock. Holes are rare.
- Y=2: ~60% chance of bedrock. More holes.
- Y=3: ~40% chance of bedrock. A visible pattern.
- Y=4: ~20% chance of bedrock. The sparsest pattern, and the easiest one for identifying a location.
The algorithm uses the world seed, the X/Z coordinates and the Y level to initialize a pseudo-random generator (Java LCG). The result is deterministic: the same seed and the same coordinates always give the same pattern. That is what makes the reverse technique possible: if you know the pattern, you can "guess" the coordinates.
Bedrock Edition generates bedrock with a different algorithm than Java Edition, so tools made for Java will not work for Bedrock Edition, and the other way around.
External tools for locating
Uses of the bedrock technique
Anarchy servers
On anarchy servers (e.g. 2b2t, constantiam, 9b9t) players often hide the locations of their bases. If someone posts a screenshot that shows bedrock at the bottom of the world, an experienced player can read the pattern and work out the base coordinates. That is why anarchy servers have a rule: never show bedrock in screenshots.
Cracking a server seed
The reverse process: if you know your coordinates (F3) and mark the bedrock pattern, you can help work out the server seed. Tools like SeedcrackerX collect data from many sources and try to reconstruct the seed.
Verifying a seed
If someone gives you a server seed but you want to verify it, compare the bedrock pattern in the game with what that seed generates in the tool. If the patterns match, the seed is genuine.
What is bedrock in Minecraft?
Bedrock is an unbreakable block at the very bottom of the Minecraft world. In the Overworld, bedrock generates at the lowest layers (formerly Y=0 to Y=4 before 1.18, now Y=-64 to Y=-60 in versions 1.18+) and forms an impassable barrier that keeps you from falling into the void.
In the Nether, bedrock forms both the floor and the ceiling, with the ceiling at layers Y=123-127. Bedrock on the Nether ceiling is especially important, because players build highways up there (Nether highways) for fast travel.
Properties of bedrock
- Unbreakable - it cannot be broken in Survival mode. Only the
/setblockcommand or Creative mode can remove it. - Blast resistance: 3,600,000 - the highest blast resistance in the game.
- Deterministic pattern - generated from the seed and the coordinates; the same seed gives the same pattern.
- Gradient distribution - bedrock density falls from 100% at Y=0 to 20% at Y=4.
How the bedrock location technique works
The key property of bedrock is that it is deterministic. The bedrock generation algorithm in Minecraft uses three parameters:
- World seed - the number that defines the whole world.
- X and Z coordinates - the block's position on the horizontal plane.
- Y coordinate - the layer (0-4 in the Overworld before 1.18).
For each block the game computes a pseudo-random value and compares it with the threshold for that Y layer. If the value is below the threshold, the block is bedrock. Because the algorithm is deterministic, the same set (seed, X, Y, Z) always gives the same result.
This means the process can be reversed: if you know the world seed and the bedrock pattern (which blocks are bedrock and which are stone or air), you can calculate at which X/Z coordinates that pattern occurs. This is especially effective at layer Y=4, where bedrock covers only 20% of the area: a sparse pattern is easier to identify unambiguously.
Why Y=4 works best
At Y=0 bedrock covers 100%, so there is no pattern to analyze. At Y=4 bedrock is only about 20% of the blocks, which creates a unique, sparse pattern. The less bedrock there is, the more distinctive the pattern and the easier it is to locate. Layer Y=3 (40%) also gives good results, but Y=4 is preferred.
Use on anarchy servers
The bedrock location technique is especially popular on anarchy servers: servers with no rules, where players can steal, grief and fight without restrictions. The most famous example is 2b2t (2builders2tools), the oldest anarchy server in Minecraft.
How it is used
- Player A posts a screenshot of their base that shows the bedrock at the bottom.
- Player B reads the bedrock pattern from the screenshot.
- Player B enters the pattern into a tool (for example BedrockFinder) along with the server's seed.
- The tool calculates the X/Z coordinates where that pattern occurs.
- Player B teleports to those coordinates and finds Player A's base.
How to protect yourself
- Don't show bedrock - make sure the bottom of the world is not visible in your screenshots.
- Hide your coordinates - turn off the HUD and the F3 debug screen before taking screenshots.
- Build far away - bases far from spawn (100,000+ blocks) are harder to find.
- Don't share an approximate location - even a rough area gives away too much.
- Cover your bedrock - hide the bedrock in your base behind other blocks so it is not visible.
Seed cracking
The bedrock technique is part of a broader practice called seed cracking: working out a server's seed from observations in the game. Depending on the tool, seed cracking uses several kinds of seed-dependent data:
- Bedrock patterns - deterministic and dependent on the seed.
- Structure positions - villages, temples and strongholds have deterministic positions.
- Biome borders - the transitions between biomes depend on the seed.
- Tree positions - in generated chunks, trees have fixed positions.
Tools such as SeedcrackerX collect this kind of data from the world as you explore. By collecting enough of it, a tool can narrow down the number of possible seeds and eventually work out the server's seed. Once you know the seed, you have access to the full map of the world: the locations of all structures, biomes and resources.
Bedrock in the Nether
The Nether has bedrock on both the floor (Y=0-4) and the ceiling (Y=123-127). The bedrock on the ceiling is especially interesting:
- Nether roof - the space above the bedrock ceiling. Players use glitches to get onto the "Nether roof" and build highways there (fast travel without mobs).
- Ceiling analysis - the bedrock pattern on the ceiling is also deterministic and can be used for location.
- Bedrock glitches - there are techniques for "breaking through" bedrock (headless piston, ender pearl glitch), but Mojang gradually patches them.
Frequently asked questions
What is bedrock in Minecraft?
Bedrock is an unbreakable block at the bottom of the world. In the Overworld it generates at Y=0 to Y=4 (Y=-64 to -60 in 1.18+), and in the Nether it forms both the floor (Y=0-4) and the ceiling (Y=123-127). It cannot be broken in Survival mode, and it protects you from falling into the void.
How does the bedrock pattern reveal a player's position?
Bedrock is generated deterministically: the same world seed and the same coordinates always produce the same pattern. If you know the server's seed and have a recorded bedrock pattern (for example from a screenshot), you can calculate the exact X/Z coordinates with tools such as BedrockFinder. The technique is used mainly on anarchy servers. The best results come from the Y=4 layer.
Which Y layer is best for reading the bedrock pattern?
Layer Y=4 is the best for reading patterns, because it has only a 20% chance of bedrock, so the pattern is sparse and easier to identify. At Y=0 bedrock covers 100% of the area (there is no pattern), and layers Y=1-3 have patterns of progressively lower density.
Does the bedrock technique work in Bedrock Edition?
The technique works in both editions, but the bedrock generation algorithms are different. Tools made for Java Edition will not give correct results in Bedrock Edition, and the other way around. Most community tools are made for Java Edition.
How large an area of bedrock do I need to record?
The minimum grid is 8x8 blocks, but the larger the grid, the more accurate the result. A 16x16 grid (a whole chunk) gives a practically unambiguous result. A 5x5 grid is too small for a full analysis, but it is enough to demonstrate the technique. For a full analysis, use external tools.
Can I protect my base from the bedrock technique?
Yes. Never post screenshots that show the bedrock under your base, and don't share coordinates, not even approximate ones. On anarchy servers, use mods that hide the HUD and the F3 coordinates before you take screenshots. Cover the bedrock in your base with other blocks, and build far from spawn (100k+ blocks).
What else is bedrock analysis used for?
Besides locating bases, bedrock analysis helps with cracking a server's seed (seed cracking). Seed cracking tools work from several kinds of in-game data, such as bedrock patterns, structures and biomes, and reconstruct the server's seed. Once you know the seed, you can find every structure in the world.