diff --git a/src/pocketmine/level/Level.php b/src/pocketmine/level/Level.php
index 738fb1391..fc48c33ed 100644
--- a/src/pocketmine/level/Level.php
+++ b/src/pocketmine/level/Level.php
@@ -116,6 +116,8 @@ class Level implements ChunkManager, Metadatable{
 	private static $chunkLoaderCounter = 1;
 	public static $COMPRESSION_LEVEL = 8;
 
+	const Y_MASK = 0xFF;
+	const Y_MAX = 0x100; //256
 
 	const BLOCK_UPDATE_NORMAL = 1;
 	const BLOCK_UPDATE_RANDOM = 2;
@@ -265,17 +267,17 @@ class Level implements ChunkManager, Metadatable{
 	}
 
 	public static function blockHash(int $x, int $y, int $z){
-		return PHP_INT_SIZE === 8 ? (($x & 0xFFFFFFF) << 35) | (($y & 0x7f) << 28) | ($z & 0xFFFFFFF) : $x . ":" . $y . ":" . $z;
+		return PHP_INT_SIZE === 8 ? (($x & 0xFFFFFFF) << 36) | (($y & Level::Y_MASK) << 28) | ($z & 0xFFFFFFF) : $x . ":" . $y . ":" . $z;
 	}
 
 	public static function chunkBlockHash(int $x, int $y, int $z) : int{
-		return ($x << 11) | ($z << 7) | $y;
+		return ($x << 12) | ($z << 8) | $y;
 	}
 
 	public static function getBlockXYZ($hash, &$x, &$y, &$z){
 		if(PHP_INT_SIZE === 8){
-			$x = ($hash >> 35) << 36 >> 36;
-			$y = (($hash >> 28) & 0x7f);// << 57 >> 57; //it's always positive
+			$x = $hash >> 36;
+			$y = $hash >> 28; //it's always positive
 			$z = ($hash & 0xFFFFFFF) << 36 >> 36;
 		}else{
 			$hash = explode(":", $hash);
@@ -287,7 +289,7 @@ class Level implements ChunkManager, Metadatable{
 
 	public static function getXZ($hash, &$x, &$z){
 		if(PHP_INT_SIZE === 8){
-			$x = ($hash >> 32) << 32 >> 32;
+			$x = $hash >> 32;
 			$z = ($hash & 0xFFFFFFFF) << 32 >> 32;
 		}else{
 			$hash = explode(":", $hash);
@@ -1204,10 +1206,10 @@ class Level implements ChunkManager, Metadatable{
 		$chunk = $this->getChunk($pos->x >> 4, $pos->z >> 4, false);
 		$level = 0;
 		if($chunk !== null){
-			$level = $chunk->getBlockSkyLight($pos->x & 0x0f, $pos->y & 0x7f, $pos->z & 0x0f);
+			$level = $chunk->getBlockSkyLight($pos->x & 0x0f, $pos->y & Level::Y_MASK, $pos->z & 0x0f);
 			//TODO: decrease light level by time of day
 			if($level < 15){
-				$level = max($chunk->getBlockLight($pos->x & 0x0f, $pos->y & 0x7f, $pos->z & 0x0f));
+				$level = max($chunk->getBlockLight($pos->x & 0x0f, $pos->y & Level::Y_MASK, $pos->z & 0x0f));
 			}
 		}
 
@@ -1222,7 +1224,7 @@ class Level implements ChunkManager, Metadatable{
 	 * @return int bitmap, (id << 4) | data
 	 */
 	public function getFullBlock(int $x, int $y, int $z) : int{
-		return $this->getChunk($x >> 4, $z >> 4, false)->getFullBlock($x & 0x0f, $y & 0x7f, $z & 0x0f);
+		return $this->getChunk($x >> 4, $z >> 4, false)->getFullBlock($x & 0x0f, $y & Level::Y_MASK, $z & 0x0f);
 	}
 
 	/**
@@ -1238,8 +1240,8 @@ class Level implements ChunkManager, Metadatable{
 		$index = Level::blockHash($pos->x, $pos->y, $pos->z);
 		if($cached and isset($this->blockCache[$index])){
 			return $this->blockCache[$index];
-		}elseif($pos->y >= 0 and $pos->y < 128 and isset($this->chunks[$chunkIndex = Level::chunkHash($pos->x >> 4, $pos->z >> 4)])){
-			$fullState = $this->chunks[$chunkIndex]->getFullBlock($pos->x & 0x0f, $pos->y & 0x7f, $pos->z & 0x0f);
+		}elseif($pos->y >= 0 and $pos->y < $this->provider->getWorldHeight() and isset($this->chunks[$chunkIndex = Level::chunkHash($pos->x >> 4, $pos->z >> 4)])){
+			$fullState = $this->chunks[$chunkIndex]->getFullBlock($pos->x & 0x0f, $pos->y & Level::Y_MASK, $pos->z & 0x0f);
 		}else{
 			$fullState = 0;
 		}
@@ -1370,11 +1372,11 @@ class Level implements ChunkManager, Metadatable{
 	 */
 	public function setBlock(Vector3 $pos, Block $block, bool $direct = false, bool $update = true) : bool{
 		$pos = $pos->floor();
-		if($pos->y < 0 or $pos->y >= 128){
+		if($pos->y < 0 or $pos->y >= $this->provider->getWorldHeight()){
 			return false;
 		}
 
-		if($this->getChunk($pos->x >> 4, $pos->z >> 4, true)->setBlock($pos->x & 0x0f, $pos->y & 0x7f, $pos->z & 0x0f, $block->getId(), $block->getDamage())){
+		if($this->getChunk($pos->x >> 4, $pos->z >> 4, true)->setBlock($pos->x & 0x0f, $pos->y & Level::Y_MASK, $pos->z & 0x0f, $block->getId(), $block->getDamage())){
 			if(!($pos instanceof Position)){
 				$pos = $this->temporalPosition->setComponents($pos->x, $pos->y, $pos->z);
 			}
@@ -1611,7 +1613,8 @@ class Level implements ChunkManager, Metadatable{
 		$target = $this->getBlock($vector);
 		$block = $target->getSide($face);
 
-		if($block->y > 127 or $block->y < 0){
+		if($block->y >= $this->provider->getWorldHeight() or $block->y < 0){
+			//TODO: build height limit messages for custom world heights and mcregion cap
 			return false;
 		}
 
@@ -1859,7 +1862,7 @@ class Level implements ChunkManager, Metadatable{
 		$chunk = $this->getChunk($pos->x >> 4, $pos->z >> 4, false);
 
 		if($chunk !== null){
-			return $chunk->getTile($pos->x & 0x0f, $pos->y & 0xff, $pos->z & 0x0f);
+			return $chunk->getTile($pos->x & 0x0f, $pos->y & Level::Y_MASK, $pos->z & 0x0f);
 		}
 
 		return null;
@@ -1899,7 +1902,7 @@ class Level implements ChunkManager, Metadatable{
 	 * @return int 0-255
 	 */
 	public function getBlockIdAt(int $x, int $y, int $z) : int{
-		return $this->getChunk($x >> 4, $z >> 4, true)->getBlockId($x & 0x0f, $y & 0x7f, $z & 0x0f);
+		return $this->getChunk($x >> 4, $z >> 4, true)->getBlockId($x & 0x0f, $y & Level::Y_MASK, $z & 0x0f);
 	}
 
 	/**
@@ -1912,7 +1915,7 @@ class Level implements ChunkManager, Metadatable{
 	 */
 	public function setBlockIdAt(int $x, int $y, int $z, int $id){
 		unset($this->blockCache[Level::blockHash($x, $y, $z)]);
-		$this->getChunk($x >> 4, $z >> 4, true)->setBlockId($x & 0x0f, $y & 0x7f, $z & 0x0f, $id & 0xff);
+		$this->getChunk($x >> 4, $z >> 4, true)->setBlockId($x & 0x0f, $y & Level::Y_MASK, $z & 0x0f, $id & 0xff);
 
 		if(!isset($this->changedBlocks[$index = Level::chunkHash($x >> 4, $z >> 4)])){
 			$this->changedBlocks[$index] = [];
@@ -1933,7 +1936,7 @@ class Level implements ChunkManager, Metadatable{
 	 * @return int 16-bit
 	 */
 	public function getBlockExtraDataAt(int $x, int $y, int $z) : int{
-		return $this->getChunk($x >> 4, $z >> 4, true)->getBlockExtraData($x & 0x0f, $y & 0x7f, $z & 0x0f);
+		return $this->getChunk($x >> 4, $z >> 4, true)->getBlockExtraData($x & 0x0f, $y & Level::Y_MASK, $z & 0x0f);
 	}
 
 	/**
@@ -1946,7 +1949,7 @@ class Level implements ChunkManager, Metadatable{
 	 * @param int $data
 	 */
 	public function setBlockExtraDataAt(int $x, int $y, int $z, int $id, int $data){
-		$this->getChunk($x >> 4, $z >> 4, true)->setBlockExtraData($x & 0x0f, $y & 0x7f, $z & 0x0f, ($data << 8) | $id);
+		$this->getChunk($x >> 4, $z >> 4, true)->setBlockExtraData($x & 0x0f, $y & Level::Y_MASK, $z & 0x0f, ($data << 8) | $id);
 
 		$this->sendBlockExtraData($x, $y, $z, $id, $data);
 	}
@@ -1961,7 +1964,7 @@ class Level implements ChunkManager, Metadatable{
 	 * @return int 0-15
 	 */
 	public function getBlockDataAt(int $x, int $y, int $z) : int{
-		return $this->getChunk($x >> 4, $z >> 4, true)->getBlockData($x & 0x0f, $y & 0x7f, $z & 0x0f);
+		return $this->getChunk($x >> 4, $z >> 4, true)->getBlockData($x & 0x0f, $y & Level::Y_MASK, $z & 0x0f);
 	}
 
 	/**
@@ -1974,7 +1977,7 @@ class Level implements ChunkManager, Metadatable{
 	 */
 	public function setBlockDataAt(int $x, int $y, int $z, int $data){
 		unset($this->blockCache[Level::blockHash($x, $y, $z)]);
-		$this->getChunk($x >> 4, $z >> 4, true)->setBlockData($x & 0x0f, $y & 0x7f, $z & 0x0f, $data & 0x0f);
+		$this->getChunk($x >> 4, $z >> 4, true)->setBlockData($x & 0x0f, $y & Level::Y_MASK, $z & 0x0f, $data & 0x0f);
 
 		if(!isset($this->changedBlocks[$index = Level::chunkHash($x >> 4, $z >> 4)])){
 			$this->changedBlocks[$index] = [];
@@ -1995,7 +1998,7 @@ class Level implements ChunkManager, Metadatable{
 	 * @return int 0-15
 	 */
 	public function getBlockSkyLightAt(int $x, int $y, int $z) : int{
-		return $this->getChunk($x >> 4, $z >> 4, true)->getBlockSkyLight($x & 0x0f, $y & 0x7f, $z & 0x0f);
+		return $this->getChunk($x >> 4, $z >> 4, true)->getBlockSkyLight($x & 0x0f, $y & Level::Y_MASK, $z & 0x0f);
 	}
 
 	/**
@@ -2007,7 +2010,7 @@ class Level implements ChunkManager, Metadatable{
 	 * @param int $level 0-15
 	 */
 	public function setBlockSkyLightAt(int $x, int $y, int $z, int $level){
-		$this->getChunk($x >> 4, $z >> 4, true)->setBlockSkyLight($x & 0x0f, $y & 0x7f, $z & 0x0f, $level & 0x0f);
+		$this->getChunk($x >> 4, $z >> 4, true)->setBlockSkyLight($x & 0x0f, $y & Level::Y_MASK, $z & 0x0f, $level & 0x0f);
 	}
 
 	/**
@@ -2020,7 +2023,7 @@ class Level implements ChunkManager, Metadatable{
 	 * @return int 0-15
 	 */
 	public function getBlockLightAt(int $x, int $y, int $z) : int{
-		return $this->getChunk($x >> 4, $z >> 4, true)->getBlockLight($x & 0x0f, $y & 0x7f, $z & 0x0f);
+		return $this->getChunk($x >> 4, $z >> 4, true)->getBlockLight($x & 0x0f, $y & Level::Y_MASK, $z & 0x0f);
 	}
 
 	/**
@@ -2032,7 +2035,7 @@ class Level implements ChunkManager, Metadatable{
 	 * @param int $level 0-15
 	 */
 	public function setBlockLightAt(int $x, int $y, int $z, int $level){
-		$this->getChunk($x >> 4, $z >> 4, true)->setBlockLight($x & 0x0f, $y & 0x7f, $z & 0x0f, $level & 0x0f);
+		$this->getChunk($x >> 4, $z >> 4, true)->setBlockLight($x & 0x0f, $y & Level::Y_MASK, $z & 0x0f, $level & 0x0f);
 	}
 
 	/**
@@ -2205,7 +2208,7 @@ class Level implements ChunkManager, Metadatable{
 	 * @param int $x
 	 * @param int $z
 	 *
-	 * @return int 0-127
+	 * @return int 0-255
 	 */
 	public function getHighestBlockAt(int $x, int $z) : int{
 		return $this->getChunk($x >> 4, $z >> 4, true)->getHighestBlockAt($x & 0x0f, $z & 0x0f);
@@ -2572,12 +2575,13 @@ class Level implements ChunkManager, Metadatable{
 			$spawn = $this->getSpawnLocation();
 		}
 		if($spawn instanceof Vector3){
+			$max = $this->provider->getWorldHeight();
 			$v = $spawn->floor();
 			$chunk = $this->getChunk($v->x >> 4, $v->z >> 4, false);
 			$x = $v->x & 0x0f;
 			$z = $v->z & 0x0f;
 			if($chunk !== null){
-				$y = (int) min(126, $v->y);
+				$y = (int) min($max - 2, $v->y);
 				$wasAir = ($chunk->getBlockId($x, $y - 1, $z) === 0);
 				for(; $y > 0; --$y){
 					$b = $chunk->getFullBlock($x, $y, $z);
@@ -2592,7 +2596,7 @@ class Level implements ChunkManager, Metadatable{
 					}
 				}
 
-				for(; $y >= 0 and $y < 128; ++$y){
+				for(; $y >= 0 and $y < $max; ++$y){
 					$b = $chunk->getFullBlock($x, $y + 1, $z);
 					$block = Block::get($b >> 4, $b & 0x0f);
 					if(!$this->isFullBlock($block)){
diff --git a/src/pocketmine/level/SimpleChunkManager.php b/src/pocketmine/level/SimpleChunkManager.php
index 8ffba5c6b..360070824 100644
--- a/src/pocketmine/level/SimpleChunkManager.php
+++ b/src/pocketmine/level/SimpleChunkManager.php
@@ -47,7 +47,7 @@ class SimpleChunkManager implements ChunkManager{
 	 */
 	public function getBlockIdAt(int $x, int $y, int $z) : int{
 		if($chunk = $this->getChunk($x >> 4, $z >> 4)){
-			return $chunk->getBlockId($x & 0xf, $y & 0x7f, $z & 0xf);
+			return $chunk->getBlockId($x & 0xf, $y & Level::Y_MASK, $z & 0xf);
 		}
 		return 0;
 	}
@@ -62,7 +62,7 @@ class SimpleChunkManager implements ChunkManager{
 	 */
 	public function setBlockIdAt(int $x, int $y, int $z, int $id){
 		if($chunk = $this->getChunk($x >> 4, $z >> 4)){
-			$chunk->setBlockId($x & 0xf, $y & 0x7f, $z & 0xf, $id);
+			$chunk->setBlockId($x & 0xf, $y & Level::Y_MASK, $z & 0xf, $id);
 		}
 	}
 
@@ -77,7 +77,7 @@ class SimpleChunkManager implements ChunkManager{
 	 */
 	public function getBlockDataAt(int $x, int $y, int $z) : int{
 		if($chunk = $this->getChunk($x >> 4, $z >> 4)){
-			return $chunk->getBlockData($x & 0xf, $y & 0x7f, $z & 0xf);
+			return $chunk->getBlockData($x & 0xf, $y & Level::Y_MASK, $z & 0xf);
 		}
 		return 0;
 	}
@@ -92,7 +92,7 @@ class SimpleChunkManager implements ChunkManager{
 	 */
 	public function setBlockDataAt(int $x, int $y, int $z, int $data){
 		if($chunk = $this->getChunk($x >> 4, $z >> 4)){
-			$chunk->setBlockData($x & 0xf, $y & 0x7f, $z & 0xf, $data);
+			$chunk->setBlockData($x & 0xf, $y & Level::Y_MASK, $z & 0xf, $data);
 		}
 	}
 
diff --git a/src/pocketmine/level/format/generic/EmptySubChunk.php b/src/pocketmine/level/format/generic/EmptySubChunk.php
index 6046f301e..423a65197 100644
--- a/src/pocketmine/level/format/generic/EmptySubChunk.php
+++ b/src/pocketmine/level/format/generic/EmptySubChunk.php
@@ -38,16 +38,16 @@ class EmptySubChunk extends SubChunk{
 		return 0;
 	}
 
-	public function setBlockId(int $x, int $y, int $z, int $id){
-
+	public function setBlockId(int $x, int $y, int $z, int $id) : bool{
+		return false;
 	}
 
 	public function getBlockData(int $x, int $y, int $z) : int{
 		return 0;
 	}
 
-	public function setBlockData(int $x, int $y, int $z, int $data){
-
+	public function setBlockData(int $x, int $y, int $z, int $data) : bool{
+		return false;
 	}
 
 	public function getFullBlock(int $x, int $y, int $z) : int{
@@ -55,23 +55,23 @@ class EmptySubChunk extends SubChunk{
 	}
 
 	public function setBlock(int $x, int $y, int $z, $id = null, $data = null) : bool{
-
+		return false;
 	}
 
 	public function getBlockSkyLight(int $x, int $y, int $z) : int{
 		return 15;
 	}
 
-	public function setBlockSkyLight(int $x, int $y, int $z, int $level){
-
+	public function setBlockSkyLight(int $x, int $y, int $z, int $level) : bool{
+		return false;
 	}
 
 	public function getBlockLight(int $x, int $y, int $z) : int{
 		return 0;
 	}
 
-	public function setBlockLight(int $x, int $y, int $z, int $level){
-
+	public function setBlockLight(int $x, int $y, int $z, int $level) : bool{
+		return false;
 	}
 	
 	public function getBlockIdColumn(int $x, int $z) : string{
diff --git a/src/pocketmine/level/format/generic/GenericChunk.php b/src/pocketmine/level/format/generic/GenericChunk.php
index 2e90fd1c1..d9b691ac1 100644
--- a/src/pocketmine/level/format/generic/GenericChunk.php
+++ b/src/pocketmine/level/format/generic/GenericChunk.php
@@ -164,7 +164,11 @@ class GenericChunk implements Chunk{
 	}
 
 	public function setBlock(int $x, int $y, int $z, $blockId = null, $meta = null) : bool{
-		return $this->getSubChunk($y >> 4, true)->setBlock($x, $y & 0x0f, $z, $blockId !== null ? ($blockId & 0xff) : null, $meta !== null ? ($meta & 0x0f) : null);
+		if($this->getSubChunk($y >> 4, true)->setBlock($x, $y & 0x0f, $z, $blockId !== null ? ($blockId & 0xff) : null, $meta !== null ? ($meta & 0x0f) : null)){
+			$this->hasChanged = true;
+			return true;
+		}
+		return false;
 	}
 
 	public function getBlockId(int $x, int $y, int $z) : int{
@@ -172,7 +176,9 @@ class GenericChunk implements Chunk{
 	}
 
 	public function setBlockId(int $x, int $y, int $z, int $id){
-		$this->getSubChunk($y >> 4, true)->setBlockId($x, $y & 0x0f, $z, $id);
+		if($this->getSubChunk($y >> 4, true)->setBlockId($x, $y & 0x0f, $z, $id)){
+			$this->hasChanged = true;
+		}
 	}
 
 	public function getBlockData(int $x, int $y, int $z) : int{
@@ -180,7 +186,9 @@ class GenericChunk implements Chunk{
 	}
 
 	public function setBlockData(int $x, int $y, int $z, int $data){
-		$this->getSubChunk($y >> 4)->setBlockData($x, $y & 0x0f, $z, $data);
+		if($this->getSubChunk($y >> 4)->setBlockData($x, $y & 0x0f, $z, $data)){
+			$this->hasChanged = true;
+		}
 	}
 
 	public function getBlockExtraData(int $x, int $y, int $z) : int{
@@ -202,7 +210,9 @@ class GenericChunk implements Chunk{
 	}
 
 	public function setBlockSkyLight(int $x, int $y, int $z, int $level){
-		$this->getSubChunk($y >> 4)->setBlockSkyLight($x, $y & 0x0f, $z, $level);
+		if($this->getSubChunk($y >> 4)->setBlockSkyLight($x, $y & 0x0f, $z, $level)){
+			$this->hasChanged = true;
+		}
 	}
 
 	public function getBlockLight(int $x, int $y, int $z) : int{
@@ -210,7 +220,9 @@ class GenericChunk implements Chunk{
 	}
 
 	public function setBlockLight(int $x, int $y, int $z, int $level){
-		$this->getSubChunk($y >> 4)->setBlockLight($x, $y & 0x0f, $z, $level);
+		if($this->getSubChunk($y >> 4)->setBlockLight($x, $y & 0x0f, $z, $level)){
+			$this->hasChanged = true;
+		}
 	}
 
 	public function getHighestBlockAt(int $x, int $z, bool $useHeightMap = true) : int{
diff --git a/src/pocketmine/level/format/generic/SubChunk.php b/src/pocketmine/level/format/generic/SubChunk.php
index dd09f3d81..62e4af0e7 100644
--- a/src/pocketmine/level/format/generic/SubChunk.php
+++ b/src/pocketmine/level/format/generic/SubChunk.php
@@ -59,8 +59,9 @@ class SubChunk{
 		return ord($this->ids{($x << 8) | ($z << 4) | $y});
 	}
 
-	public function setBlockId(int $x, int $y, int $z, int $id){
+	public function setBlockId(int $x, int $y, int $z, int $id) : bool{
 		$this->ids{($x << 8) | ($z << 4) | $y} = chr($id);
+		return true;
 	}
 
 	public function getBlockData(int $x, int $y, int $z) : int{
@@ -72,15 +73,14 @@ class SubChunk{
 		}
 	}
 
-	public function setBlockData(int $x, int $y, int $z, int $data){
+	public function setBlockData(int $x, int $y, int $z, int $data) : bool{
 		$i = ($x << 7) | ($z << 3) | ($y >> 1);
-		$current = ord($this->data{$i});
 		if(($y & 1) === 0){
-			$this->data{$i} = chr(($current & 0xf0) | ($data & 0x0f));
+			$this->data{$i} = chr((ord($this->data{$i}) & 0xf0) | ($data & 0x0f));
 		}else{
-			$this->data{$i} = chr((($data & 0x0f) << 4) | ($current & 0x0f));
+			$this->data{$i} = chr((($data & 0x0f) << 4) | (ord($this->data{$i}) & 0x0f));
 		}
-		$this->hasChanged = true;
+		return true;
 	}
 
 	public function getFullBlock(int $x, int $y, int $z) : int{
@@ -128,7 +128,7 @@ class SubChunk{
 		}
 	}
 
-	public function setBlockSkyLight(int $x, int $y, int $z, int $level){
+	public function setBlockSkyLight(int $x, int $y, int $z, int $level) : bool{
 		$i = ($x << 7) + ($z << 3) + ($y >> 1);
 		$byte = ord($this->skyLight{$i});
 		if(($y & 1) === 0){
@@ -136,6 +136,7 @@ class SubChunk{
 		}else{
 			$this->skyLight{$i} = chr((($level & 0x0f) << 4) | ($byte & 0x0f));
 		}
+		return true;
 	}
 
 	public function getBlockLight(int $x, int $y, int $z) : int{
@@ -147,7 +148,7 @@ class SubChunk{
 		}
 	}
 
-	public function setBlockLight(int $x, int $y, int $z, int $level){
+	public function setBlockLight(int $x, int $y, int $z, int $level) : bool{
 		$i = ($x << 7) + ($z << 3) + ($y >> 1);
 		$byte = ord($this->blockLight{$i});
 		if(($y & 1) === 0){
@@ -155,6 +156,7 @@ class SubChunk{
 		}else{
 			$this->blockLight{$i} = chr((($level & 0x0f) << 4) | ($byte & 0x0f));
 		}
+		return true;
 	}
 
 	public function getHighestBlockAt(int $x, int $z) : int{