diff --git a/src/constants.h b/src/constants.h
index fc0ae25f..bd40c278 100644
--- a/src/constants.h
+++ b/src/constants.h
@@ -6,9 +6,12 @@
 #define CHUNK_W 16
 #define CHUNK_H 256
 #define CHUNK_D 16
+
+/* Chunk volume (count of voxels per Chunk) */
 #define CHUNK_VOL (CHUNK_W * CHUNK_H * CHUNK_D)
 
-#define BLOCK_VOID (blockid_t)((2 << (sizeof(blockid_t)*8)) - 1)
+/* BLOCK_VOID is block id used to mark non-existing voxel (voxel of missing chunk) */
+#define BLOCK_VOID (blockid_t)((2 << (sizeof(blockid_t)*CHAR_BIT)) - 1)
 
 inline uint vox_index(int x, int y, int z, int w, int d) {
 	return (y * d + z) * w + x;
diff --git a/src/declarations.cpp b/src/declarations.cpp
index 2f89985d..a6984798 100644
--- a/src/declarations.cpp
+++ b/src/declarations.cpp
@@ -20,8 +20,9 @@ void initialize_assets(AssetsLoader* loader) {
 
 // All in-game definitions (blocks, items, etc..)
 void setup_definitions() {
-	for (size_t i = 0; i < 256; i++)
+	for (size_t i = 0; i < 256; i++) {
 		Block::blocks[i] = nullptr;
+	}
 
 	Block* block = new Block(BLOCK_AIR, 0);
 	block->drawGroup = 1;
diff --git a/src/files/WorldFiles.cpp b/src/files/WorldFiles.cpp
index 681b2896..94798429 100644
--- a/src/files/WorldFiles.cpp
+++ b/src/files/WorldFiles.cpp
@@ -1,6 +1,7 @@
 #include "WorldFiles.h"
 
 #include "files.h"
+#include "rle.h"
 #include "../window/Camera.h"
 #include "../objects/Player.h"
 #include "../physics/Hitbox.h"
@@ -12,6 +13,7 @@
 #include <cassert>
 #include <iostream>
 #include <cstdint>
+#include <memory>
 #include <fstream>
 #include <iostream>
 
@@ -20,12 +22,11 @@
 #define SECTION_FLAGS 3
 #define PLAYER_FLAG_FLIGHT 0x1
 #define PLAYER_FLAG_NOCLIP 0x2
-#define CHUNK_DATA_LEN (CHUNK_VOL*sizeof(voxel))
 
 using glm::ivec2;
 using glm::vec3;
-
-int64_t WorldFiles::totalCompressed = 0;
+using std::ios;
+using std::unique_ptr;
 
 int bytes2Int(const ubyte* src, size_t offset){
 	return (src[offset] << 24) | (src[offset+1] << 16) | (src[offset+2] << 8) | (src[offset+3]);
@@ -55,18 +56,18 @@ float bytes2Float(ubyte* src, uint offset){
 }
 
 WorldFiles::WorldFiles(std::string directory, size_t mainBufferCapacity) : directory(directory){
-	mainBufferIn = new ubyte[CHUNK_DATA_LEN];
-	mainBufferOut = new ubyte[mainBufferCapacity];
+	mainBufferIn = new ubyte[CHUNK_DATA_LEN * 2];
+	compressionBuffer = new ubyte[CHUNK_DATA_LEN * 2];
 }
 
 WorldFiles::~WorldFiles(){
 	delete[] mainBufferIn;
-	delete[] mainBufferOut;
+	delete[] compressionBuffer;
 	for (auto it = regions.begin(); it != regions.end(); it++){
 	    WorldRegion region = it->second;
 	    if (region.chunksData == nullptr)
 	    	continue;
-	    for (unsigned int i = 0; i < REGION_VOL; i++){
+	    for (size_t i = 0; i < REGION_VOL; i++){
 	    	delete[] region.chunksData[i];
 	    }
 	    delete[] region.chunksData;
@@ -74,37 +75,44 @@ WorldFiles::~WorldFiles(){
 	regions.clear();
 }
 
-void WorldFiles::put(const ubyte* chunkData, int x, int y){
-	assert(chunkData != nullptr);
+void WorldFiles::put(Chunk* chunk){
+	assert(chunk != nullptr);
 
-	int regionX = floordiv(x, REGION_SIZE);
-	int regionY = floordiv(y, REGION_SIZE);
+	int regionX = floordiv(chunk->x, REGION_SIZE);
+	int regionY = floordiv(chunk->z, REGION_SIZE);
 
-	int localX = x - (regionX * REGION_SIZE);
-	int localY = y - (regionY * REGION_SIZE);
+	int localX = chunk->x - (regionX * REGION_SIZE);
+	int localY = chunk->z - (regionY * REGION_SIZE);
 
 	ivec2 key(regionX, regionY);
 
 	auto found = regions.find(key);
 	if (found == regions.end()) {
 		ubyte** chunksData = new ubyte*[REGION_VOL];
+		uint32_t* compressedSizes = new uint32_t[REGION_VOL];
 		for (uint i = 0; i < REGION_VOL; i++) {
 			chunksData[i] = nullptr;
 		}
-		regions[key] = { chunksData, true };
+		regions[key] = { chunksData, compressedSizes, true };
 	}
 
 	WorldRegion& region = regions[key];
 	region.unsaved = true;
-	ubyte* targetChunk = region.chunksData[localY * REGION_SIZE + localX];
-	if (targetChunk == nullptr){
-		targetChunk = new ubyte[CHUNK_DATA_LEN];
-		region.chunksData[localY * REGION_SIZE + localX] = targetChunk;
-		totalCompressed += CHUNK_DATA_LEN;
+	size_t chunk_index = localY * REGION_SIZE + localX;
+	ubyte* target_chunk = region.chunksData[chunk_index];
+	if (target_chunk) {
+		delete[] target_chunk;
 	}
-	for (uint i = 0; i < CHUNK_DATA_LEN; i++)
-		targetChunk[i] = chunkData[i];
 
+	ubyte* chunk_data = chunk->encode();
+	size_t compressedSize = extrle::encode(chunk_data, CHUNK_DATA_LEN, compressionBuffer);
+	delete[] chunk_data;
+	ubyte* data = new ubyte[compressedSize];
+	for (size_t i = 0; i < compressedSize; i++) {
+		data[i] = compressionBuffer[i];
+	}
+	region.chunksData[chunk_index] = data;
+	region.compressedSizes[chunk_index] = compressedSize;
 }
 
 std::string WorldFiles::getRegionFile(int x, int y) {
@@ -115,9 +123,7 @@ std::string WorldFiles::getPlayerFile() {
 	return directory + "/player.bin";
 }
 
-bool WorldFiles::getChunk(int x, int y, ubyte* out){
-	assert(out != nullptr);
-
+ubyte* WorldFiles::getChunk(int x, int y){
 	int regionX = floordiv(x, REGION_SIZE);
 	int regionY = floordiv(y, REGION_SIZE);
 
@@ -131,21 +137,31 @@ bool WorldFiles::getChunk(int x, int y, ubyte* out){
 
 	auto found = regions.find(key);
 	if (found == regions.end()) {
-		return readChunk(x, y, out);
+		ubyte** chunksData = new ubyte * [REGION_VOL];
+		uint32_t* compressedSizes = new uint32_t[REGION_VOL];
+		for (uint i = 0; i < REGION_VOL; i++) {
+			chunksData[i] = nullptr;
+		}
+		regions[key] = { chunksData, compressedSizes, true };
 	}
 
-	WorldRegion& region = found->second;
-	ubyte* chunk = region.chunksData[chunkIndex];
-	if (chunk == nullptr)
-		return readChunk(x,y,out);
-	for (uint i = 0; i < CHUNK_DATA_LEN; i++)
-		out[i] = chunk[i];
-	return true;
+	WorldRegion& region = regions[key];
+	ubyte* data = region.chunksData[chunkIndex];
+	if (data == nullptr) {
+		data = readChunkData(x, y, region.compressedSizes[chunkIndex]);
+		if (data) {
+			region.chunksData[chunkIndex] = data;
+		}
+	}
+	if (data) {
+		ubyte* decompressed = new ubyte[CHUNK_DATA_LEN];
+		extrle::decode(data, region.compressedSizes[chunkIndex], decompressed);
+		return decompressed;
+	}
+	return nullptr;
 }
 
-bool WorldFiles::readChunk(int x, int y, ubyte* out){
-	assert(out != nullptr);
-
+ubyte* WorldFiles::readChunkData(int x, int y, uint32_t& length){
 	int regionX = floordiv(x, REGION_SIZE);
 	int regionY = floordiv(y, REGION_SIZE);
 
@@ -157,39 +173,35 @@ bool WorldFiles::readChunk(int x, int y, ubyte* out){
 	std::string filename = getRegionFile(regionX, regionY);
 	std::ifstream input(filename, std::ios::binary);
 	if (!input.is_open()){
-		return false;
+		return nullptr;
 	}
+	input.seekg(0, ios::end);
+	size_t file_size = input.tellg();
+	size_t table_offset = file_size - REGION_VOL * 4;
 
 	uint32_t offset;
-	input.seekg(chunkIndex*4);
+	input.seekg(table_offset + chunkIndex * 4);
 	input.read((char*)(&offset), 4);
-	// Ordering bytes from big-endian to machine order (any, just reading)
-	offset = bytes2Int((const unsigned char*)(&offset), 0);
-	//assert (offset < 1000000);
+	offset = bytes2Int((const ubyte*)(&offset), 0);
 	if (offset == 0){
 		input.close();
-		return false;
+		return nullptr;
 	}
 	input.seekg(offset);
 	input.read((char*)(&offset), 4);
-	size_t compressedSize = bytes2Int((const ubyte*)(&offset), 0);
-	input.read((char*)mainBufferIn, compressedSize);
+	length = bytes2Int((const ubyte*)(&offset), 0);
+	ubyte* data = new ubyte[length];
+	input.read((char*)data, length);
 	input.close();
-
-	decompressRLE((ubyte*)mainBufferIn, compressedSize, (ubyte*)out, CHUNK_DATA_LEN);
-
-	return true;
+	return data;
 }
 
 void WorldFiles::write(){
 	for (auto it = regions.begin(); it != regions.end(); it++){
 		if (it->second.chunksData == nullptr || !it->second.unsaved)
 			continue;
-
 		ivec2 key = it->first;
-
-		unsigned int size = writeRegion(mainBufferOut, key.x, key.y, it->second.chunksData);
-		write_binary_file(getRegionFile(key.x, key.y), (const char*)mainBufferOut, size);
+		writeRegion(key.x, key.y, it->second);
 	}
 }
 
@@ -238,7 +250,7 @@ bool WorldFiles::readPlayer(Player* player) {
 			break;
 		case SECTION_FLAGS:
 			{
-				unsigned char flags = data[offset++];
+				ubyte flags = data[offset++];
 				player->flight = flags & PLAYER_FLAG_FLIGHT;
 				player->noclip = flags & PLAYER_FLAG_NOCLIP;
 			}
@@ -250,39 +262,45 @@ bool WorldFiles::readPlayer(Player* player) {
 	return true;
 }
 
-uint WorldFiles::writeRegion(ubyte* out, int x, int y, ubyte** region){
-	uint offset = REGION_VOL * 4;
-	for (uint i = 0; i < offset; i++)
-		out[i] = 0;
 
-	ubyte* compressed = new ubyte[CHUNK_DATA_LEN];
-	for (int i = 0; i < REGION_VOL; i++){
-		ubyte* chunk = region[i];
-		if (chunk == nullptr){
-			chunk = new ubyte[CHUNK_DATA_LEN];
-			if (readChunk((i % REGION_SIZE) + x * REGION_SIZE, (i / REGION_SIZE) + y * REGION_SIZE, chunk)){
-				region[i] = chunk;
-				totalCompressed += CHUNK_DATA_LEN;
-			} else {
-				delete[] chunk;
-				chunk = nullptr;
-			}
-		}
-
-		if (chunk == nullptr){
-			int2Bytes(0, out, i*4);
-		} else {
-			int2Bytes(offset, out, i*4);
-
-			uint compressedSize = compressRLE(chunk, CHUNK_DATA_LEN, compressed);
-
-			int2Bytes(compressedSize, out, offset);
-			offset += 4;
-
-			for (uint j = 0; j < compressedSize; j++)
-				out[offset++] = compressed[j];
+void WorldFiles::writeRegion(int x, int y, WorldRegion& entry){
+	ubyte** region = entry.chunksData;
+	uint32_t* sizes = entry.compressedSizes;
+	for (size_t i = 0; i < REGION_VOL; i++) {
+		int chunk_x = (i % REGION_SIZE) + x * REGION_SIZE;
+		int chunk_y = (i / REGION_SIZE) + y * REGION_SIZE;
+		if (region[i] == nullptr) {
+			region[i] = readChunkData(chunk_x, chunk_y, sizes[i]);
 		}
 	}
-	delete[] compressed;
-	return offset;
+
+	char header[10] = ".VOXREG";
+	header[8] = REGION_FORMAT_VERSION;
+	header[9] = 0; // flags
+	std::ofstream file(getRegionFile(x, y), ios::out | ios::binary);
+	file.write(header, 10);
+
+	size_t offset = 10;
+	char intbuf[4]{};
+	uint offsets[REGION_VOL]{};
+	
+	for (size_t i = 0; i < REGION_VOL; i++) {
+		ubyte* chunk = region[i];
+		if (chunk == nullptr){
+			offsets[i] = 0;
+		} else {
+			offsets[i] = offset;
+
+			size_t compressedSize = sizes[i];
+			int2Bytes(compressedSize, (ubyte*)intbuf, 0);
+			offset += 4 + compressedSize;
+
+			file.write(intbuf, 4);
+			file.write((const char*)chunk, compressedSize);
+		}
+	}
+	for (size_t i = 0; i < REGION_VOL; i++) {
+		int2Bytes(offsets[i], (ubyte*)intbuf, 0);
+		file.write(intbuf, 4);
+	}
 }
diff --git a/src/files/WorldFiles.h b/src/files/WorldFiles.h
index 20628d95..221058da 100644
--- a/src/files/WorldFiles.h
+++ b/src/files/WorldFiles.h
@@ -11,34 +11,36 @@
 
 #include "../typedefs.h"
 
-class Player;
-
 #define REGION_SIZE_BIT 5
 #define REGION_SIZE (1 << (REGION_SIZE_BIT))
 #define REGION_VOL ((REGION_SIZE) * (REGION_SIZE))
+#define REGION_FORMAT_VERSION 1
+
+class Player;
+class Chunk;
 
 struct WorldRegion {
 	ubyte** chunksData;
+	uint32_t* compressedSizes;
 	bool unsaved;
 };
 
 class WorldFiles {
 public:
-	static int64_t totalCompressed;
 	std::unordered_map<glm::ivec2, WorldRegion> regions;
 	std::string directory;
 	ubyte* mainBufferIn;
-	ubyte* mainBufferOut;
+	ubyte* compressionBuffer;
 
 	WorldFiles(std::string directory, size_t mainBufferCapacity);
 	~WorldFiles();
 
-	void put(const ubyte* chunkData, int x, int y);
+	void put(Chunk* chunk);
 
 	bool readPlayer(Player* player);
-	bool readChunk(int x, int y, ubyte* out);
-	bool getChunk(int x, int y, ubyte* out);
-	uint writeRegion(ubyte* out, int x, int y, ubyte** region);
+	ubyte* readChunkData(int x, int y, uint32_t& length);
+	ubyte* getChunk(int x, int y);
+	void writeRegion(int x, int y, WorldRegion& entry);
 	void writePlayer(Player* player);
 	void write();
 
diff --git a/src/files/files.cpp b/src/files/files.cpp
index 573d1f4b..51e3b558 100644
--- a/src/files/files.cpp
+++ b/src/files/files.cpp
@@ -55,56 +55,3 @@ char* read_binary_file(std::string filename, size_t& length) {
 	input.close();
 	return data.release();
 }
-
-// returns decompressed length
-size_t decompressRLE(const ubyte* src, size_t length, ubyte* dst, size_t targetLength){
-	size_t offset = 0;
-	for (size_t i = 0; i < length;){
-		unsigned char counter = src[i++];
-		unsigned char c = src[i++];
-		for (unsigned int j = 0; j <= counter; j++){
-			dst[offset++] = c;
-		}
-	}
-	return offset;
-}
-
-size_t calcRLE(const ubyte* src, size_t length) {
-	size_t offset = 0;
-	size_t counter = 0;
-	ubyte c = src[0];
-	for (size_t i = 0; i < length; i++){
-		ubyte cnext = src[i];
-		if (cnext != c || counter == 255){
-			offset += 2;
-			c = cnext;
-			counter = 0;
-		} else {
-			counter++;
-		}
-	}
-	return offset + 2;
-}
-
-// max result size = length * 2; returns compressed length
-size_t compressRLE(const ubyte* src, size_t length, ubyte* dst) {
-	if (length == 0)
-		return 0;
-	size_t offset = 0;
-	uint counter = 0;
-	ubyte c = src[0];
-	for (size_t i = 1; i < length; i++){
-		ubyte cnext = src[i];
-		if (cnext != c || counter == 255){
-			dst[offset++] = counter;
-			dst[offset++] = c;
-			c = cnext;
-			counter = 0;
-		} else {
-			counter++;
-		}
-	}
-	dst[offset++] = counter;
-	dst[offset++] = c;
-	return offset;
-}
diff --git a/src/files/files.h b/src/files/files.h
index b760529d..87ca7d4d 100644
--- a/src/files/files.h
+++ b/src/files/files.h
@@ -7,11 +7,6 @@
 extern bool write_binary_file(std::string filename, const char* data, size_t size);
 extern unsigned int append_binary_file(std::string filename, const char* data, size_t size);
 extern bool read_binary_file(std::string filename, char* data, size_t size);
-extern bool read_binary_file(std::string filename, char* data, size_t offset, size_t size);
 extern char* read_binary_file(std::string filename, size_t& length);
 
-extern size_t calcRLE(const ubyte* src, size_t length);
-extern size_t compressRLE(const ubyte* src, size_t length, ubyte* dst);
-extern size_t decompressRLE(const ubyte* src, size_t length, ubyte* dst, size_t targetLength);
-
 #endif /* FILES_FILES_H_ */
diff --git a/src/files/rle.cpp b/src/files/rle.cpp
new file mode 100644
index 00000000..5a5c5714
--- /dev/null
+++ b/src/files/rle.cpp
@@ -0,0 +1,90 @@
+#include "rle.h"
+
+size_t rle::decode(const ubyte* src, size_t srclen, ubyte* dst) {
+	size_t offset = 0;
+	for (size_t i = 0; i < srclen;) {
+		ubyte len = src[i++];
+		ubyte c = src[i++];
+		for (size_t j = 0; j <= len; j++) {
+			dst[offset++] = c;
+		}
+	}
+	return offset;
+}
+
+size_t rle::encode(const ubyte* src, size_t srclen, ubyte* dst) {
+	if (srclen == 0) {
+		return 0;
+	}
+	size_t offset = 0;
+	ubyte counter = 0;
+	ubyte c = src[0];
+	for (size_t i = 1; i < srclen; i++) {
+		ubyte cnext = src[i];
+		if (cnext != c || counter == 255) {
+			dst[offset++] = counter;
+			dst[offset++] = c;
+			c = cnext;
+			counter = 0;
+		}
+		else {
+			counter++;
+		}
+	}
+	dst[offset++] = counter;
+	dst[offset++] = c;
+	return offset;
+}
+
+
+size_t extrle::decode(const ubyte* src, size_t srclen, ubyte* dst) {
+	size_t offset = 0;
+	for (size_t i = 0; i < srclen;) {
+		uint len = src[i++];
+		if (len & 0x80) {
+			len &= 0x7F;
+			len |= ((uint)src[i++]) << 7;
+		}
+		ubyte c = src[i++];
+		for (size_t j = 0; j <= len; j++) {
+			dst[offset++] = c;
+		}
+	}
+	return offset;
+}
+
+size_t extrle::encode(const ubyte* src, size_t srclen, ubyte* dst) {
+	if (srclen == 0) {
+		return 0;
+	}
+	size_t offset = 0;
+	uint counter = 0;
+	ubyte c = src[0];
+	for (size_t i = 1; i < srclen; i++) {
+		ubyte cnext = src[i];
+		if (cnext != c || counter == max_sequence) {
+			if (counter >= 0x80) {
+				dst[offset++] = 0x80 | (counter & 0x7F);
+				dst[offset++] = counter >> 7;
+			}
+			else {
+				dst[offset++] = counter;
+			}
+			dst[offset++] = c;
+			c = cnext;
+			counter = 0;
+		}
+		else {
+			counter++;
+		}
+	}
+	if (counter >= 0x80) {
+		dst[offset++] = 0x80 | (counter & 0x7F);
+		dst[offset++] = counter >> 7;
+	}
+	else {
+		dst[offset++] = counter;
+	}
+	dst[offset++] = c;
+	return offset;
+}
diff --git a/src/files/rle.h b/src/files/rle.h
new file mode 100644
index 00000000..b12a1adc
--- /dev/null
+++ b/src/files/rle.h
@@ -0,0 +1,17 @@
+#ifndef FILES_RLE_H_
+#define FILES_RLE_H_
+
+#include "../typedefs.h"
+
+namespace rle {
+	size_t encode(const ubyte* src, size_t length, ubyte* dst);
+	size_t decode(const ubyte* src, size_t length, ubyte* dst);
+}
+
+namespace extrle {
+	constexpr uint max_sequence = 0x7FFF;
+	size_t encode(const ubyte* src, size_t length, ubyte* dst);
+	size_t decode(const ubyte* src, size_t length, ubyte* dst);
+}
+
+#endif // FILES_RLE_H_
\ No newline at end of file
diff --git a/src/voxels/Chunk.cpp b/src/voxels/Chunk.cpp
index 6fecb180..fc372437 100644
--- a/src/voxels/Chunk.cpp
+++ b/src/voxels/Chunk.cpp
@@ -4,8 +4,10 @@
 
 Chunk::Chunk(int xpos, int zpos) : x(xpos), z(zpos){
 	voxels = new voxel[CHUNK_VOL];
-	for (unsigned int i = 0; i < CHUNK_VOL; i++)
-		voxels[i].id = 1;
+	for (size_t i = 0; i < CHUNK_VOL; i++) {
+		voxels[i].id = 2;
+		voxels[i].states = 0;
+	}
 	lightmap = new Lightmap();
 	renderData.vertices = nullptr;
 }
@@ -36,3 +38,27 @@ Chunk* Chunk::clone() const {
 	return other;
 }
 
+/** 
+  Current chunk format:
+	[voxel_ids...][voxel_states...];
+*/
+ubyte* Chunk::encode() const {
+	ubyte* buffer = new ubyte[CHUNK_DATA_LEN];
+	for (size_t i = 0; i < CHUNK_VOL; i++) {
+		buffer[i] = voxels[i].id;
+		buffer[CHUNK_VOL + i] = voxels[i].states;
+	}
+	return buffer;
+}
+
+/**
+  @return true if all is fine
+*/
+bool Chunk::decode(ubyte* data) {
+	for (size_t i = 0; i < CHUNK_VOL; i++) {
+		voxel& vox = voxels[i];
+		vox.id = data[i];
+		vox.states = data[CHUNK_VOL + i];
+	}
+	return true;
+}
diff --git a/src/voxels/Chunk.h b/src/voxels/Chunk.h
index 329dbed8..b3b8e2b6 100644
--- a/src/voxels/Chunk.h
+++ b/src/voxels/Chunk.h
@@ -9,6 +9,7 @@
 #define CHUNK_LOADED 0x4
 #define CHUNK_LIGHTED 0x8
 #define CHUNK_UNSAVED 0x10
+#define CHUNK_DATA_LEN (CHUNK_VOL*2)
 
 struct voxel;
 class Lightmap;
@@ -59,6 +60,9 @@ public:
 	inline void setLighted(bool flag) {BITSET(flags, CHUNK_LIGHTED, flag);}
 
 	inline void setReady(bool flag) {BITSET(flags, CHUNK_READY, flag);}
+
+	ubyte* encode() const;
+	bool decode(ubyte* data);
 };
 
 #endif /* VOXELS_CHUNK_H_ */
diff --git a/src/voxels/Chunks.cpp b/src/voxels/Chunks.cpp
index 3a5d8961..165a90ab 100644
--- a/src/voxels/Chunks.cpp
+++ b/src/voxels/Chunks.cpp
@@ -5,6 +5,7 @@
 #include "WorldGenerator.h"
 #include "../lighting/Lightmap.h"
 #include "../files/WorldFiles.h"
+#include "../world/LevelEvents.h"
 
 #include "../graphics/Mesh.h"
 #include "../voxmaths.h"
@@ -15,8 +16,8 @@
 using glm::vec3;
 using std::shared_ptr;
 
-Chunks::Chunks(int w, int d, int ox, int oz) : w(w), d(d), ox(ox), oz(oz){
-	volume = w*d;
+Chunks::Chunks(int w, int d, int ox, int oz, LevelEvents* events) : w(w), d(d), ox(ox), oz(oz), events(events) {
+	volume = (size_t)w*(size_t)d;
 	chunks = new shared_ptr<Chunk>[volume];
 	chunksSecond = new shared_ptr<Chunk>[volume];
 
@@ -258,7 +259,8 @@ void Chunks::translate(WorldFiles* worldFiles, int dx, int dz){
 			if (chunk == nullptr)
 				continue;
 			if (nx < 0 || nz < 0 || nx >= w || nz >= d){
-				worldFiles->put((const ubyte*)chunk->voxels, chunk->x, chunk->z);
+				events->trigger(EVT_CHUNK_HIDDEN, chunk.get());
+				worldFiles->put(chunk.get());
 				chunksCount--;
 				continue;
 			}
@@ -292,6 +294,10 @@ bool Chunks::putChunk(shared_ptr<Chunk> chunk) {
 
 void Chunks::clear(){
 	for (size_t i = 0; i < volume; i++){
+		Chunk* chunk = chunks[i].get();
+		if (chunk) {
+			events->trigger(EVT_CHUNK_HIDDEN, chunk);
+		}
 		chunks[i] = nullptr;
 	}
 	chunksCount = 0;
diff --git a/src/voxels/Chunks.h b/src/voxels/Chunks.h
index 509b7671..2e871c18 100644
--- a/src/voxels/Chunks.h
+++ b/src/voxels/Chunks.h
@@ -11,6 +11,7 @@ class VoxelRenderer;
 class Chunk;
 class voxel;
 class WorldFiles;
+class LevelEvents;
 
 class Chunks {
 public:
@@ -20,8 +21,9 @@ public:
 	size_t chunksCount;
 	int w,d;
 	int ox,oz;
+	LevelEvents* events;
 
-	Chunks(int w, int d, int ox, int oz);
+	Chunks(int w, int d, int ox, int oz, LevelEvents* events);
 	~Chunks();
 
 	bool putChunk(std::shared_ptr<Chunk> chunk);
diff --git a/src/voxels/ChunksController.cpp b/src/voxels/ChunksController.cpp
index c697d3c3..ae13c0f0 100644
--- a/src/voxels/ChunksController.cpp
+++ b/src/voxels/ChunksController.cpp
@@ -79,9 +79,12 @@ bool ChunksController::loadVisible(WorldFiles* worldFiles){
 
 	chunk = shared_ptr<Chunk>(new Chunk(nearX+ox, nearZ+oz));
 	level->chunksStorage->store(chunk);
-	if (worldFiles->getChunk(chunk->x, chunk->z, (ubyte*)chunk->voxels))
+	ubyte* data = worldFiles->getChunk(chunk->x, chunk->z);
+	if (data) {
+		chunk->decode(data);
 		chunk->setLoaded(true);
-
+		delete[] data;
+	}
 	chunks->putChunk(chunk);
 
 	if (!chunk->isLoaded()) {
@@ -90,8 +93,9 @@ bool ChunksController::loadVisible(WorldFiles* worldFiles){
 	}
 
 	for (size_t i = 0; i < CHUNK_VOL; i++) {
-		if (Block::blocks[chunk->voxels[i].id] == nullptr) {
-			std::cout << "corruped block detected at " << i << " of chunk " << chunk->x << "x" << chunk->z << std::endl;
+		blockid_t id = chunk->voxels[i].id;
+		if (Block::blocks[id] == nullptr) {
+			std::cout << "corruped block detected at " << i << " of chunk " << chunk->x << "x" << chunk->z << " -> " << (int)id << std::endl;
 			chunk->voxels[i].id = 11;
 		}
 	}
diff --git a/src/voxels/ChunksStorage.cpp b/src/voxels/ChunksStorage.cpp
index ec7f7e1b..dba41672 100644
--- a/src/voxels/ChunksStorage.cpp
+++ b/src/voxels/ChunksStorage.cpp
@@ -29,6 +29,13 @@ shared_ptr<Chunk> ChunksStorage::get(int x, int z) const {
 	return found->second;
 }
 
+void ChunksStorage::remove(int x, int z) {
+	auto found = chunksMap.find(ivec2(x, z));
+	if (found != chunksMap.end()) {
+		chunksMap.erase(found->first);
+	}
+}
+
 // some magic code
 void ChunksStorage::getVoxels(VoxelsVolume* volume) const {
 	voxel* voxels = volume->getVoxels();
diff --git a/src/voxels/ChunksStorage.h b/src/voxels/ChunksStorage.h
index d15c99c4..24c415b7 100644
--- a/src/voxels/ChunksStorage.h
+++ b/src/voxels/ChunksStorage.h
@@ -20,6 +20,7 @@ public:
 
 	std::shared_ptr<Chunk> get(int x, int y) const;
 	void store(std::shared_ptr<Chunk> chunk);
+	void remove(int x, int y);
 	void getVoxels(VoxelsVolume* volume) const;
 
 	light_t getLight(int x, int y, int z, ubyte channel) const;
diff --git a/src/world/Level.cpp b/src/world/Level.cpp
index 2b7d9db3..c9be21ba 100644
--- a/src/world/Level.cpp
+++ b/src/world/Level.cpp
@@ -1,6 +1,8 @@
 #include "Level.h"
 #include "World.h"
+#include "LevelEvents.h"
 #include "../lighting/Lighting.h"
+#include "../voxels/Chunk.h"
 #include "../voxels/Chunks.h"
 #include "../voxels/ChunksController.h"
 #include "../voxels/ChunksStorage.h"
@@ -9,19 +11,24 @@
 #include "../physics/PhysicsSolver.h"
 #include "../objects/Player.h"
 
-Level::Level(World* world, Player* player, Chunks* chunks, ChunksStorage* chunksStorage, PhysicsSolver* physics) :
-	world(world),
-	player(player),
-	chunks(chunks),
-	chunksStorage(chunksStorage),
-	physics(physics) {
+Level::Level(World* world, Player* player, Chunks* chunks, ChunksStorage* chunksStorage, PhysicsSolver* physics, LevelEvents* events) :
+		world(world),
+		player(player),
+		chunks(chunks),
+		chunksStorage(chunksStorage),
+		physics(physics),
+		events(events) {
 	lighting = new Lighting(chunks);
 	chunksController = new ChunksController(this, chunks, lighting);
 	playerController = new PlayerController(this);
+	events->listen(EVT_CHUNK_HIDDEN, [this](lvl_event_type type, Chunk* chunk) {
+		this->chunksStorage->remove(chunk->x, chunk->z);
+	});
 }
 
 Level::~Level(){
 	delete chunks;
+	delete events;
 	delete physics;
 	delete player;
 	delete lighting;
diff --git a/src/world/Level.h b/src/world/Level.h
index 6c981fea..03d2079e 100644
--- a/src/world/Level.h
+++ b/src/world/Level.h
@@ -4,6 +4,7 @@
 class World;
 class Player;
 class Chunks;
+class LevelEvents;
 class Lighting;
 class PhysicsSolver;
 class ChunksController;
@@ -20,7 +21,8 @@ public:
 	Lighting* lighting;
 	ChunksController* chunksController;
 	PlayerController* playerController;
-	Level(World* world, Player* player, Chunks* chunks, ChunksStorage* chunksStorage, PhysicsSolver* physics);
+	LevelEvents* events;
+	Level(World* world, Player* player, Chunks* chunks, ChunksStorage* chunksStorage, PhysicsSolver* physics, LevelEvents* events);
 	~Level();
 
 	void update(float delta, bool interactions);
diff --git a/src/world/LevelEvents.cpp b/src/world/LevelEvents.cpp
new file mode 100644
index 00000000..260aecb5
--- /dev/null
+++ b/src/world/LevelEvents.cpp
@@ -0,0 +1,16 @@
+#include "LevelEvents.h"
+#include "../voxels/Chunk.h"
+
+using std::vector;
+
+void LevelEvents::listen(lvl_event_type type, chunk_event_func func) {
+	auto& callbacks = chunk_callbacks[type];
+	callbacks.push_back(func);
+}
+
+void LevelEvents::trigger(lvl_event_type type, Chunk* chunk) {
+	auto& callbacks = chunk_callbacks[type];
+	for (chunk_event_func func : callbacks) {
+		func(type, chunk);
+	}
+}
\ No newline at end of file
diff --git a/src/world/LevelEvents.h b/src/world/LevelEvents.h
new file mode 100644
index 00000000..ae4362b9
--- /dev/null
+++ b/src/world/LevelEvents.h
@@ -0,0 +1,23 @@
+#ifndef WORLD_LEVEL_EVENTS_H_
+#define WORLD_LEVEL_EVENTS_H_
+
+#include <functional>
+#include <vector>
+#include <unordered_map>
+
+class Chunk;
+
+enum lvl_event_type {
+	EVT_CHUNK_HIDDEN,
+};
+
+typedef std::function<void(lvl_event_type, Chunk*)> chunk_event_func;
+
+class LevelEvents {
+	std::unordered_map<lvl_event_type, std::vector<chunk_event_func>> chunk_callbacks;
+public:
+	void listen(lvl_event_type type, chunk_event_func func);
+	void trigger(lvl_event_type type, Chunk* chunk);
+};
+
+#endif // WORLD_LEVEL_EVENTS_H_
\ No newline at end of file
diff --git a/src/world/World.cpp b/src/world/World.cpp
index adaa578d..0bd357c5 100644
--- a/src/world/World.cpp
+++ b/src/world/World.cpp
@@ -10,11 +10,12 @@
 #include "../objects/Player.h"
 #include "../physics/PhysicsSolver.h"
 #include "../window/Camera.h"
+#include "../world/LevelEvents.h"
 
 using std::shared_ptr;
 
 World::World(std::string name, std::string directory, int seed) : name(name), seed(seed) {
-	wfile = new WorldFiles(directory, REGION_VOL * (CHUNK_VOL * 2 + 8));
+	wfile = new WorldFiles(directory, REGION_VOL * (CHUNK_DATA_LEN * 2 + 8));
 }
 
 World::~World(){
@@ -24,11 +25,11 @@ World::~World(){
 void World::write(Level* level) {
 	Chunks* chunks = level->chunks;
 
-	for (unsigned int i = 0; i < chunks->volume; i++) {
+	for (size_t i = 0; i < chunks->volume; i++) {
 		shared_ptr<Chunk> chunk = chunks->chunks[i];
 		if (chunk == nullptr || !chunk->isUnsaved())
 			continue;
-		wfile->put((const ubyte*)chunk->voxels, chunk->x, chunk->z);
+		wfile->put(chunk.get());
 	}
 
 	wfile->write();
@@ -37,7 +38,8 @@ void World::write(Level* level) {
 
 Level* World::loadLevel(Player* player) {
 	ChunksStorage* storage = new ChunksStorage();
-	Level* level = new Level(this, player, new Chunks(16, 16, 0, 0), storage, new PhysicsSolver(vec3(0, -19.6f, 0)));
+	LevelEvents* events = new LevelEvents();
+	Level* level = new Level(this, player, new Chunks(16, 16, 0, 0, events), storage, new PhysicsSolver(vec3(0, -19.6f, 0)), events);
 	wfile->readPlayer(player);
 
 	Camera* camera = player->camera;
diff --git a/src/world_render.cpp b/src/world_render.cpp
index 6d0a2b5f..19b8ba1d 100644
--- a/src/world_render.cpp
+++ b/src/world_render.cpp
@@ -17,6 +17,7 @@
 #include "voxels/Block.h"
 #include "world/World.h"
 #include "world/Level.h"
+#include "world/LevelEvents.h"
 #include "objects/Player.h"
 #include "Assets.h"
 #include "player_control.h"
@@ -30,6 +31,9 @@ WorldRenderer::WorldRenderer(Level* level, Assets* assets) : assets(assets), lev
 	lineBatch = new LineBatch(4096);
 	batch3d = new Batch3D(1024);
 	renderer = new ChunksRenderer(level);
+	level->events->listen(EVT_CHUNK_HIDDEN, [this](lvl_event_type type, Chunk* chunk) {
+		renderer->unload(chunk);
+	});
 }
 
 WorldRenderer::~WorldRenderer() {