diff --git a/protocol-generator/src/data/input.rs b/protocol-generator/src/backend.rs
similarity index 88%
rename from protocol-generator/src/data/input.rs
rename to protocol-generator/src/backend.rs
index b7a2c30..d8b3ced 100644
--- a/protocol-generator/src/data/input.rs
+++ b/protocol-generator/src/backend.rs
@@ -2,23 +2,23 @@ use linked_hash_map::LinkedHashMap;
 use serde::Deserialize;
 
 #[derive(Debug, Deserialize)]
-pub struct Protocol {
-    pub handshaking: ProtocolState,
-    pub status: ProtocolState,
-    pub login: ProtocolState,
+pub struct ProtocolHandler {
+    pub handshaking: Protocol,
+    pub status: Protocol,
+    pub login: Protocol,
     #[serde(rename = "play")]
-    pub game: ProtocolState,
+    pub game: Protocol,
 }
 
 #[derive(Debug, Deserialize)]
 #[serde(rename_all = "camelCase")]
-pub struct ProtocolState {
-    pub to_client: ProtocolData,
-    pub to_server: ProtocolData,
+pub struct Protocol {
+    pub to_client: Packets,
+    pub to_server: Packets,
 }
 
 #[derive(Debug, Deserialize)]
-pub struct ProtocolData {
+pub struct Packets {
     pub types: LinkedHashMap<String, Vec<Data>>,
 }
 
diff --git a/protocol-generator/src/data/mod.rs b/protocol-generator/src/data/mod.rs
deleted file mode 100644
index 7d1a548..0000000
--- a/protocol-generator/src/data/mod.rs
+++ /dev/null
@@ -1,2 +0,0 @@
-pub mod input;
-pub mod output;
diff --git a/protocol-generator/src/main.rs b/protocol-generator/src/main.rs
index 4820043..ffbd346 100644
--- a/protocol-generator/src/main.rs
+++ b/protocol-generator/src/main.rs
@@ -1,18 +1,19 @@
-mod data;
-
-use crate::data::input;
-use handlebars::*;
-use heck::{CamelCase, SnakeCase};
-
-use crate::data::input::{Container, Data, ProtocolData, ProtocolState};
-use crate::data::output;
-use serde::Serialize;
-use serde_json::json;
-use std::collections::HashMap;
 use std::fs::File;
 use std::io::Write;
+
+use crate::mappings::CodeMappings;
+use crate::transformer::transform_protocol;
+use handlebars::*;
+use heck::SnakeCase;
+use serde::Serialize;
+use serde_json::json;
 use structopt::StructOpt;
 
+pub mod backend;
+pub mod frontend;
+pub mod mappings;
+pub mod transformer;
+
 #[derive(StructOpt)]
 #[structopt(name = "protocol-generator")]
 struct Opt {
@@ -32,25 +33,31 @@ pub fn main() {
     let protocol_data_file =
         File::open(protocol_data_file_name).expect("Failed to open protocol data file");
 
-    let protocol_input: input::Protocol =
+    let protocol_input: backend::ProtocolHandler =
         serde_json::from_reader(protocol_data_file).expect("Failed to parse protocol data");
 
+    let mappings = CodeMappings {};
+
     let protocols = vec![
         (
-            transform_protocol_state(output::State::Handshake, &protocol_input.handshaking),
-            output::State::Handshake,
+            transform_protocol(
+                &mappings,
+                frontend::State::Handshake,
+                &protocol_input.handshaking,
+            ),
+            frontend::State::Handshake,
         ),
         (
-            transform_protocol_state(output::State::Status, &protocol_input.status),
-            output::State::Status,
+            transform_protocol(&mappings, frontend::State::Status, &protocol_input.status),
+            frontend::State::Status,
         ),
         (
-            transform_protocol_state(output::State::Login, &protocol_input.login),
-            output::State::Login,
+            transform_protocol(&mappings, frontend::State::Login, &protocol_input.login),
+            frontend::State::Login,
         ),
         (
-            transform_protocol_state(output::State::Game, &protocol_input.game),
-            output::State::Game,
+            transform_protocol(&mappings, frontend::State::Game, &protocol_input.game),
+            frontend::State::Game,
         ),
     ];
 
@@ -97,264 +104,24 @@ fn create_template_engine() -> Handlebars<'static> {
     template_engine
 }
 
-fn transform_protocol_state(
-    state: output::State,
-    protocol_state: &ProtocolState,
-) -> output::Protocol {
-    let server_bound_packets = transform_protocol_data(
-        protocol_state,
-        &protocol_state.to_server,
-        output::Bound::Server,
-    );
-    let client_bound_packets = transform_protocol_data(
-        protocol_state,
-        &protocol_state.to_client,
-        output::Bound::Client,
-    );
-
-    output::Protocol {
-        state,
-        server_bound_packets,
-        client_bound_packets,
-    }
-}
-
-fn transform_protocol_data(
-    protocol_state: &ProtocolState,
-    protocol_data: &ProtocolData,
-    bound: output::Bound,
-) -> Vec<output::Packet> {
-    let packet_ids = get_packet_ids(protocol_data);
-    let mut packets = vec![];
-
-    for (unformatted_name, data_vec) in protocol_data.types.iter() {
-        if !unformatted_name.starts_with("packet_")
-            || unformatted_name == "packet_legacy_server_list_ping"
-        {
-            continue;
-        }
-
-        let no_prefix_unformatted = unformatted_name.trim_start_matches("packet_");
-
-        let id = *packet_ids
-            .get(no_prefix_unformatted)
-            .expect("Failed to get packet id");
-
-        let packet_name = rename_packet(
-            unformatted_name,
-            &no_prefix_unformatted.to_camel_case(),
-            &bound,
-            protocol_state,
-        );
-
-        let mut fields = vec![];
-
-        for data in data_vec {
-            if let Data::Container(container_vec) = data {
-                for container in container_vec {
-                    match container {
-                        Container::Value { name, data } => match transform_field(name, data) {
-                            Some(field) => fields.push(modify_field(&packet_name, field)),
-                            None => println!(
-                                "[{}] Field \"{}\" are skipped ({:?}",
-                                packet_name, name, data
-                            ),
-                        },
-                        Container::List { name, data_vec } => {
-                            if let Some(name) = name {
-                                for data in data_vec {
-                                    match transform_field(name, data) {
-                                        Some(field) => {
-                                            fields.push(modify_field(&packet_name, field))
-                                        }
-                                        None => println!(
-                                            "[{}] Field \"{}\" are skipped ({:?})",
-                                            packet_name, name, data_vec
-                                        ),
-                                    }
-                                }
-                            }
-                        }
-                    }
-                }
-            }
-        }
-
-        let packet = output::Packet {
-            id,
-            name: packet_name,
-            fields,
-        };
-
-        packets.push(packet);
-    }
-
-    packets
-}
-
-fn get_packet_ids(protocol_data: &ProtocolData) -> HashMap<String, u8> {
-    let reversed_packet_ids = protocol_data
-        .types
-        .get("packet")
-        .and_then(|d| d.get(1))
-        .and_then(|d| match d {
-            Data::Container(data) => data.get(0),
-            _ => None,
-        })
-        .and_then(|c| match c {
-            Container::List { data_vec, .. } => data_vec.get(1),
-            _ => None,
-        })
-        .and_then(|d| match d {
-            Data::Mapper { mappings, .. } => Some(mappings),
-            _ => None,
-        })
-        .expect("Failed to get packet ids");
-
-    reversed_packet_ids
-        .into_iter()
-        .map(|(k, v)| {
-            (
-                v.clone(),
-                u8::from_str_radix(k.trim_start_matches("0x"), 16).expect("Invalid packet id"),
-            )
-        })
-        .collect()
-}
-
-fn transform_field(unformatted_field_name: &str, data: &Data) -> Option<output::Field> {
-    match data {
-        Data::Type(name) => match transform_data_type(name) {
-            Some(data_type) => Some(output::Field {
-                name: format_field_name(unformatted_field_name),
-                data_type,
-            }),
-            None => None,
-        },
-        _ => None,
-    }
-}
-
-fn transform_data_type(name: &str) -> Option<output::DataType> {
-    match name {
-        "bool" => Some(output::DataType::Boolean),
-        "i8" => Some(output::DataType::Byte),
-        "i16" => Some(output::DataType::Short),
-        "i32" => Some(output::DataType::Int { var_int: false }),
-        "i64" => Some(output::DataType::Long { var_long: false }),
-        "u8" => Some(output::DataType::UnsignedByte),
-        "u16" => Some(output::DataType::UnsignedShort),
-        "f32" => Some(output::DataType::Float),
-        "f64" => Some(output::DataType::Double),
-        "varint" => Some(output::DataType::Int { var_int: true }),
-        "varlong" => Some(output::DataType::Long { var_long: true }),
-        "string" => Some(output::DataType::String { max_length: 0 }),
-        "nbt" | "optionalNbt" => Some(output::DataType::CompoundTag),
-        "UUID" => Some(output::DataType::Uuid { hyphenated: false }),
-        "buffer" => Some(output::DataType::ByteArray { rest: false }),
-        "restBuffer" => Some(output::DataType::ByteArray { rest: true }),
-        "position" => Some(output::DataType::RefType {
-            ref_name: "Position".to_string(),
-        }),
-        "slot" => Some(output::DataType::RefType {
-            ref_name: "Option<Slot>".to_string(),
-        }),
-        "entityMetadata" => Some(output::DataType::RefType {
-            ref_name: "Metadata".to_string(),
-        }),
-        "tags" => Some(output::DataType::RefType {
-            ref_name: "TagsMap".to_string(),
-        }),
-        "option" => None,
-        _ => {
-            println!("Unknown data type \"{}\"", name);
-            None
-        }
-    }
-}
-
-fn format_field_name(unformatted_field_name: &str) -> String {
-    if unformatted_field_name == "type" {
-        String::from("type_")
-    } else {
-        unformatted_field_name.to_snake_case()
-    }
-}
-
-fn rename_packet(
-    unformatted_name: &str,
-    name: &str,
-    bound: &output::Bound,
-    protocol_state: &ProtocolState,
-) -> String {
-    let new_name = match (name, bound) {
-        ("EncryptionBegin", output::Bound::Server) => "EncryptionResponse",
-        ("EncryptionBegin", output::Bound::Client) => "EncryptionRequest",
-        ("PingStart", output::Bound::Server) => "StatusRequest",
-        ("Ping", output::Bound::Server) => "PingRequest",
-        ("ServerInfo", output::Bound::Client) => "StatusResponse",
-        ("Ping", output::Bound::Client) => "PingResponse",
-        ("Login", output::Bound::Client) => "JoinGame",
-        _ => name,
-    }
-    .to_owned();
-
-    if new_name == name
-        && protocol_state
-            .to_client
-            .types
-            .contains_key(unformatted_name)
-        && protocol_state
-            .to_server
-            .types
-            .contains_key(unformatted_name)
-    {
-        bidirectional(&new_name, bound)
-    } else {
-        new_name.to_owned()
-    }
-}
-
-fn bidirectional(name: &str, bound: &output::Bound) -> String {
-    match bound {
-        output::Bound::Server => format!("ServerBound{}", name),
-        output::Bound::Client => format!("ClientBound{}", name),
-    }
-}
-
-fn modify_field(packet_name: &str, field: output::Field) -> output::Field {
-    match (packet_name, field.name.as_str()) {
-        ("StatusResponse", "response") => field.change_type(output::DataType::RefType {
-            ref_name: "ServerStatus".to_owned(),
-        }),
-        ("Success", "uuid") => field.change_type(output::DataType::Uuid { hyphenated: true }),
-        ("Disconnect", "reason") => field.change_type(output::DataType::Chat),
-        ("ClientBoundChat", "message") => field.change_type(output::DataType::Chat),
-        ("ClientBoundChat", "position") => field.change_type(output::DataType::RefType {
-            ref_name: "MessagePosition".to_owned(),
-        }),
-        _ => field,
-    }
-}
-
 #[derive(Serialize)]
 struct GenerateContext<'a> {
     packet_enum_name: String,
-    packets: &'a Vec<output::Packet>,
+    packets: &'a Vec<frontend::Packet>,
 }
 
 fn generate_rust_file<W: Write>(
-    protocol: &output::Protocol,
+    protocol: &frontend::Protocol,
     template_engine: &Handlebars,
     mut writer: W,
 ) -> Result<(), TemplateRenderError> {
     let server_bound_ctx = GenerateContext {
-        packet_enum_name: format!("{}{}BoundPacket", &protocol.state, output::Bound::Server),
+        packet_enum_name: format!("{}{}BoundPacket", &protocol.state, frontend::Bound::Server),
         packets: &protocol.server_bound_packets,
     };
 
     let client_bound_ctx = GenerateContext {
-        packet_enum_name: format!("{}{}BoundPacket", &protocol.state, output::Bound::Client),
+        packet_enum_name: format!("{}{}BoundPacket", &protocol.state, frontend::Bound::Client),
         packets: &protocol.client_bound_packets,
     };
 
diff --git a/protocol-generator/src/mappings.rs b/protocol-generator/src/mappings.rs
new file mode 100644
index 0000000..5716322
--- /dev/null
+++ b/protocol-generator/src/mappings.rs
@@ -0,0 +1,65 @@
+use crate::backend;
+use crate::frontend;
+
+pub trait Mappings {
+    fn rename_packet(
+        &self,
+        unformatted_name: &str,
+        name: &str,
+        bound: &frontend::Bound,
+        protocol: &backend::Protocol,
+    ) -> String;
+
+    fn change_field_type(&self, packet_name: &str, field: frontend::Field) -> frontend::Field;
+}
+
+pub struct CodeMappings {}
+
+impl Mappings for CodeMappings {
+    fn rename_packet(
+        &self,
+        unformatted_name: &str,
+        name: &str,
+        bound: &frontend::Bound,
+        protocol: &backend::Protocol,
+    ) -> String {
+        let new_name = match (name, bound) {
+            ("EncryptionBegin", frontend::Bound::Server) => "EncryptionResponse",
+            ("EncryptionBegin", frontend::Bound::Client) => "EncryptionRequest",
+            ("PingStart", frontend::Bound::Server) => "StatusRequest",
+            ("Ping", frontend::Bound::Server) => "PingRequest",
+            ("ServerInfo", frontend::Bound::Client) => "StatusResponse",
+            ("Ping", frontend::Bound::Client) => "PingResponse",
+            ("Login", frontend::Bound::Client) => "JoinGame",
+            _ => name,
+        }
+        .to_owned();
+
+        if new_name == name
+            && protocol.to_client.types.contains_key(unformatted_name)
+            && protocol.to_server.types.contains_key(unformatted_name)
+        {
+            match bound {
+                frontend::Bound::Server => format!("ServerBound{}", name),
+                frontend::Bound::Client => format!("ClientBound{}", name),
+            }
+        } else {
+            new_name.to_owned()
+        }
+    }
+
+    fn change_field_type(&self, packet_name: &str, field: frontend::Field) -> frontend::Field {
+        match (packet_name, field.name.as_str()) {
+            ("StatusResponse", "response") => field.change_type(frontend::DataType::RefType {
+                ref_name: "ServerStatus".to_owned(),
+            }),
+            ("Success", "uuid") => field.change_type(frontend::DataType::Uuid { hyphenated: true }),
+            ("Disconnect", "reason") => field.change_type(frontend::DataType::Chat),
+            ("ClientBoundChat", "message") => field.change_type(frontend::DataType::Chat),
+            ("ClientBoundChat", "position") => field.change_type(frontend::DataType::RefType {
+                ref_name: "MessagePosition".to_owned(),
+            }),
+            _ => field,
+        }
+    }
+}
diff --git a/protocol-generator/src/transformer.rs b/protocol-generator/src/transformer.rs
new file mode 100644
index 0000000..20cb518
--- /dev/null
+++ b/protocol-generator/src/transformer.rs
@@ -0,0 +1,196 @@
+use crate::mappings::Mappings;
+use crate::{backend, frontend};
+use heck::{CamelCase, SnakeCase};
+use std::collections::HashMap;
+
+pub fn transform_protocol<M: Mappings>(
+    mappings: &M,
+    state: frontend::State,
+    protocol: &backend::Protocol,
+) -> frontend::Protocol {
+    let server_bound_packets = transform_packets(
+        mappings,
+        protocol,
+        &protocol.to_server,
+        frontend::Bound::Server,
+    );
+
+    let client_bound_packets = transform_packets(
+        mappings,
+        protocol,
+        &protocol.to_client,
+        frontend::Bound::Client,
+    );
+
+    frontend::Protocol {
+        state,
+        server_bound_packets,
+        client_bound_packets,
+    }
+}
+
+fn transform_packets<M: Mappings>(
+    mappings: &M,
+    protocol: &backend::Protocol,
+    packets: &backend::Packets,
+    bound: frontend::Bound,
+) -> Vec<frontend::Packet> {
+    let packet_ids = get_packet_ids(packets);
+    let mut output_packets = vec![];
+
+    for (unformatted_name, data_vec) in packets.types.iter() {
+        if !unformatted_name.starts_with("packet_")
+            || unformatted_name == "packet_legacy_server_list_ping"
+        {
+            continue;
+        }
+
+        let no_prefix_unformatted = unformatted_name.trim_start_matches("packet_");
+
+        let id = *packet_ids
+            .get(no_prefix_unformatted)
+            .expect("Failed to get packet id");
+
+        let packet_name = mappings.rename_packet(
+            unformatted_name,
+            &no_prefix_unformatted.to_camel_case(),
+            &bound,
+            protocol,
+        );
+
+        let mut fields = vec![];
+
+        for data in data_vec {
+            if let backend::Data::Container(container_vec) = data {
+                for container in container_vec {
+                    match container {
+                        backend::Container::Value { name, data } => {
+                            match transform_field(&name, &data) {
+                                Some(field) => {
+                                    fields.push(mappings.change_field_type(&packet_name, field))
+                                }
+                                None => println!(
+                                    "[{}] Field \"{}\" are skipped ({:?}",
+                                    packet_name, name, data
+                                ),
+                            }
+                        }
+                        backend::Container::List { name, data_vec } => {
+                            if let Some(name) = name {
+                                for data in data_vec {
+                                    match transform_field(&name, &data) {
+                                        Some(field) => fields
+                                            .push(mappings.change_field_type(&packet_name, field)),
+                                        None => println!(
+                                            "[{}] Field \"{}\" are skipped ({:?})",
+                                            packet_name, name, data_vec
+                                        ),
+                                    }
+                                }
+                            }
+                        }
+                    }
+                }
+            }
+        }
+
+        let packet = frontend::Packet {
+            id,
+            name: packet_name,
+            fields,
+        };
+
+        output_packets.push(packet);
+    }
+
+    output_packets
+}
+
+fn get_packet_ids(packets: &backend::Packets) -> HashMap<String, u8> {
+    let reversed_packet_ids = packets
+        .types
+        .get("packet")
+        .and_then(|d| d.get(1))
+        .and_then(|d| match d {
+            backend::Data::Container(data) => data.get(0),
+            _ => None,
+        })
+        .and_then(|c| match c {
+            backend::Container::List { data_vec, .. } => data_vec.get(1),
+            _ => None,
+        })
+        .and_then(|d| match d {
+            backend::Data::Mapper { mappings, .. } => Some(mappings),
+            _ => None,
+        })
+        .expect("Failed to get packet ids");
+
+    reversed_packet_ids
+        .into_iter()
+        .map(|(k, v)| {
+            (
+                v.clone(),
+                u8::from_str_radix(k.trim_start_matches("0x"), 16).expect("Invalid packet id"),
+            )
+        })
+        .collect()
+}
+
+fn transform_field(unformatted_field_name: &str, data: &backend::Data) -> Option<frontend::Field> {
+    match data {
+        backend::Data::Type(name) => match transform_data_type(name) {
+            Some(data_type) => Some(frontend::Field {
+                name: format_field_name(unformatted_field_name),
+                data_type,
+            }),
+            None => None,
+        },
+        _ => None,
+    }
+}
+
+fn transform_data_type(name: &str) -> Option<frontend::DataType> {
+    match name {
+        "bool" => Some(frontend::DataType::Boolean),
+        "i8" => Some(frontend::DataType::Byte),
+        "i16" => Some(frontend::DataType::Short),
+        "i32" => Some(frontend::DataType::Int { var_int: false }),
+        "i64" => Some(frontend::DataType::Long { var_long: false }),
+        "u8" => Some(frontend::DataType::UnsignedByte),
+        "u16" => Some(frontend::DataType::UnsignedShort),
+        "f32" => Some(frontend::DataType::Float),
+        "f64" => Some(frontend::DataType::Double),
+        "varint" => Some(frontend::DataType::Int { var_int: true }),
+        "varlong" => Some(frontend::DataType::Long { var_long: true }),
+        "string" => Some(frontend::DataType::String { max_length: 0 }),
+        "nbt" | "optionalNbt" => Some(frontend::DataType::CompoundTag),
+        "UUID" => Some(frontend::DataType::Uuid { hyphenated: false }),
+        "buffer" => Some(frontend::DataType::ByteArray { rest: false }),
+        "restBuffer" => Some(frontend::DataType::ByteArray { rest: true }),
+        "position" => Some(frontend::DataType::RefType {
+            ref_name: "Position".to_string(),
+        }),
+        "slot" => Some(frontend::DataType::RefType {
+            ref_name: "Option<Slot>".to_string(),
+        }),
+        "entityMetadata" => Some(frontend::DataType::RefType {
+            ref_name: "Metadata".to_string(),
+        }),
+        "tags" => Some(frontend::DataType::RefType {
+            ref_name: "TagsMap".to_string(),
+        }),
+        "option" => None,
+        _ => {
+            println!("Unknown data type \"{}\"", name);
+            None
+        }
+    }
+}
+
+fn format_field_name(unformatted_field_name: &str) -> String {
+    if unformatted_field_name == "type" {
+        String::from("type_")
+    } else {
+        unformatted_field_name.to_snake_case()
+    }
+}
diff --git a/protocol/src/data/game.rs b/protocol/src/data/game.rs
index 95e2fcb..cf94310 100644
--- a/protocol/src/data/game.rs
+++ b/protocol/src/data/game.rs
@@ -1,6 +1,4 @@
-use crate::error::{DecodeError, EncodeError};
-use crate::{impl_enum_encoder_decoder, Decoder, DecoderReadExt, Encoder, EncoderWriteExt};
-use byteorder::{BigEndian, ReadBytesExt, WriteBytesExt};
+use crate::impl_enum_encoder_decoder;
 use nbt::CompoundTag;
 use num_derive::{FromPrimitive, ToPrimitive};
 use std::io::{Read, Write};
@@ -32,31 +30,6 @@ pub struct Position {
     pub z: i32,
 }
 
-impl Encoder for Position {
-    fn encode<W: Write>(&self, writer: &mut W) -> Result<(), EncodeError> {
-        let encoded_x = (self.x & 0x3FFFFFF) as i64;
-        let encoded_y = (self.y & 0xFFF) as i64;
-        let encoded_z = (self.z & 0x3FFFFFF) as i64;
-
-        writer.write_i64::<BigEndian>((encoded_x << 38) | (encoded_z << 12) | encoded_y)?;
-        Ok(())
-    }
-}
-
-impl Decoder for Position {
-    type Output = Self;
-
-    fn decode<R: Read>(reader: &mut R) -> Result<Self::Output, DecodeError> {
-        let encoded = reader.read_i64::<BigEndian>()?;
-
-        let x = (encoded >> 38) as i32;
-        let y = (encoded & 0xFFF) as i16;
-        let z = (encoded << 26 >> 38) as i32;
-
-        Ok(Position { x, y, z })
-    }
-}
-
 #[derive(Debug)]
 pub struct Slot {
     pub id: i32,
@@ -64,86 +37,8 @@ pub struct Slot {
     pub compound_tag: CompoundTag,
 }
 
-impl Encoder for Option<Slot> {
-    fn encode<W: Write>(&self, writer: &mut W) -> Result<(), EncodeError> {
-        match self {
-            Some(slot) => {
-                writer.write_bool(true)?;
-                slot.encode(writer)
-            }
-            None => writer.write_bool(false),
-        }
-    }
-}
-
-impl Decoder for Option<Slot> {
-    type Output = Self;
-
-    fn decode<R: Read>(reader: &mut R) -> Result<Self::Output, DecodeError> {
-        if reader.read_bool()? {
-            Ok(Some(Slot::decode(reader)?))
-        } else {
-            Ok(None)
-        }
-    }
-}
-
-impl Encoder for Slot {
-    fn encode<W: Write>(&self, writer: &mut W) -> Result<(), EncodeError> {
-        writer.write_var_i32(self.id)?;
-        writer.write_u8(self.amount)?;
-        writer.write_compound_tag(&self.compound_tag)?;
-
-        Ok(())
-    }
-}
-
-impl Decoder for Slot {
-    type Output = Self;
-
-    fn decode<R: Read>(reader: &mut R) -> Result<Self::Output, DecodeError> {
-        let id = reader.read_var_i32()?;
-        let amount = reader.read_u8()?;
-        let compound_tag = reader.read_compound_tag()?;
-
-        Ok(Slot {
-            id,
-            amount,
-            compound_tag,
-        })
-    }
-}
-
 #[derive(Debug)]
 pub struct Metadata {}
 
-impl Encoder for Metadata {
-    fn encode<W: Write>(&self, writer: &mut W) -> Result<(), EncodeError> {
-        unimplemented!()
-    }
-}
-
-impl Decoder for Metadata {
-    type Output = Self;
-
-    fn decode<R: Read>(reader: &mut R) -> Result<Self::Output, DecodeError> {
-        unimplemented!()
-    }
-}
-
 #[derive(Debug)]
 pub struct TagsMap {}
-
-impl Encoder for TagsMap {
-    fn encode<W: Write>(&self, writer: &mut W) -> Result<(), EncodeError> {
-        unimplemented!()
-    }
-}
-
-impl Decoder for TagsMap {
-    type Output = Self;
-
-    fn decode<R: Read>(reader: &mut R) -> Result<Self::Output, DecodeError> {
-        unimplemented!()
-    }
-}
diff --git a/protocol/src/lib.rs b/protocol/src/lib.rs
index fdcbbc2..cb858c1 100644
--- a/protocol/src/lib.rs
+++ b/protocol/src/lib.rs
@@ -10,6 +10,7 @@ use uuid::Uuid;
 
 use data::chat::Message;
 
+use crate::data::game::{Metadata, Position, Slot, TagsMap};
 use crate::error::{DecodeError, EncodeError};
 
 pub mod data;
@@ -509,6 +510,109 @@ macro_rules! impl_json_encoder_decoder (
    );
 );
 
+impl Encoder for Position {
+    fn encode<W: Write>(&self, writer: &mut W) -> Result<(), EncodeError> {
+        let encoded_x = (self.x & 0x3FFFFFF) as i64;
+        let encoded_y = (self.y & 0xFFF) as i64;
+        let encoded_z = (self.z & 0x3FFFFFF) as i64;
+
+        writer.write_i64::<BigEndian>((encoded_x << 38) | (encoded_z << 12) | encoded_y)?;
+        Ok(())
+    }
+}
+
+impl Decoder for Position {
+    type Output = Self;
+
+    fn decode<R: Read>(reader: &mut R) -> Result<Self::Output, DecodeError> {
+        let encoded = reader.read_i64::<BigEndian>()?;
+
+        let x = (encoded >> 38) as i32;
+        let y = (encoded & 0xFFF) as i16;
+        let z = (encoded << 26 >> 38) as i32;
+
+        Ok(Position { x, y, z })
+    }
+}
+
+impl Encoder for Option<Slot> {
+    fn encode<W: Write>(&self, writer: &mut W) -> Result<(), EncodeError> {
+        match self {
+            Some(slot) => {
+                writer.write_bool(true)?;
+                slot.encode(writer)
+            }
+            None => writer.write_bool(false),
+        }
+    }
+}
+
+impl Decoder for Option<Slot> {
+    type Output = Self;
+
+    fn decode<R: Read>(reader: &mut R) -> Result<Self::Output, DecodeError> {
+        if reader.read_bool()? {
+            Ok(Some(Slot::decode(reader)?))
+        } else {
+            Ok(None)
+        }
+    }
+}
+
+impl Encoder for Slot {
+    fn encode<W: Write>(&self, writer: &mut W) -> Result<(), EncodeError> {
+        writer.write_var_i32(self.id)?;
+        writer.write_u8(self.amount)?;
+        writer.write_compound_tag(&self.compound_tag)?;
+
+        Ok(())
+    }
+}
+
+impl Decoder for Slot {
+    type Output = Self;
+
+    fn decode<R: Read>(reader: &mut R) -> Result<Self::Output, DecodeError> {
+        let id = reader.read_var_i32()?;
+        let amount = reader.read_u8()?;
+        let compound_tag = reader.read_compound_tag()?;
+
+        Ok(Slot {
+            id,
+            amount,
+            compound_tag,
+        })
+    }
+}
+
+impl Encoder for Metadata {
+    fn encode<W: Write>(&self, writer: &mut W) -> Result<(), EncodeError> {
+        unimplemented!()
+    }
+}
+
+impl Decoder for Metadata {
+    type Output = Self;
+
+    fn decode<R: Read>(reader: &mut R) -> Result<Self::Output, DecodeError> {
+        unimplemented!()
+    }
+}
+
+impl Encoder for TagsMap {
+    fn encode<W: Write>(&self, writer: &mut W) -> Result<(), EncodeError> {
+        unimplemented!()
+    }
+}
+
+impl Decoder for TagsMap {
+    type Output = Self;
+
+    fn decode<R: Read>(reader: &mut R) -> Result<Self::Output, DecodeError> {
+        unimplemented!()
+    }
+}
+
 mod var_int {
     use std::io::{Read, Write};