diff --git a/src/client/Client.js b/src/client/Client.js
index 553b9c584..203863451 100644
--- a/src/client/Client.js
+++ b/src/client/Client.js
@@ -19,6 +19,7 @@ const Invite = require('../structures/Invite');
 const OAuth2Application = require('../structures/OAuth2Application');
 const ShardClientUtil = require('../sharding/ShardClientUtil');
 const VoiceBroadcast = require('./voice/VoiceBroadcast');
+const { Error, TypeError, RangeError } = require('../errors');
 
 /**
  * The main hub for interacting with the Discord API, and the starting point for any bot.
@@ -287,7 +288,7 @@ class Client extends EventEmitter {
    */
   login(token) {
     return new Promise((resolve, reject) => {
-      if (typeof token !== 'string') throw new Error(Constants.Errors.INVALID_TOKEN);
+      if (typeof token !== 'string') throw new Error('TOKEN_INVALID');
       token = token.replace(/^Bot\s*/i, '');
       this.manager.connectToWebSocket(token, resolve, reject);
     });
@@ -375,7 +376,9 @@ class Client extends EventEmitter {
    * or -1 if the message cache lifetime is unlimited
    */
   sweepMessages(lifetime = this.options.messageCacheLifetime) {
-    if (typeof lifetime !== 'number' || isNaN(lifetime)) throw new TypeError('The lifetime must be a number.');
+    if (typeof lifetime !== 'number' || isNaN(lifetime)) {
+      throw new TypeError('CLIENT_INVALID_OPTION', 'Lifetime', 'a number');
+    }
     if (lifetime <= 0) {
       this.emit('debug', 'Didn\'t sweep messages - lifetime is unlimited');
       return -1;
@@ -524,41 +527,40 @@ class Client extends EventEmitter {
    */
   _validateOptions(options = this.options) {
     if (typeof options.shardCount !== 'number' || isNaN(options.shardCount)) {
-      throw new TypeError('The shardCount option must be a number.');
+      throw new TypeError('CLIENT_INVALID_OPTION', 'shardCount', 'a number');
     }
     if (typeof options.shardId !== 'number' || isNaN(options.shardId)) {
-      throw new TypeError('The shardId option must be a number.');
+      throw new TypeError('CLIENT_INVALID_OPTION', 'shardId', 'a number');
     }
-    if (options.shardCount < 0) throw new RangeError('The shardCount option must be at least 0.');
-    if (options.shardId < 0) throw new RangeError('The shardId option must be at least 0.');
+    if (options.shardCount < 0) throw new RangeError('CLIENT_INVALID_OPTION', 'shardCount', 'at least 0');
+    if (options.shardId < 0) throw new RangeError('CLIENT_INVALID_OPTION', 'shardId', 'at least 0');
     if (options.shardId !== 0 && options.shardId >= options.shardCount) {
-      throw new RangeError('The shardId option must be less than shardCount.');
+      throw new RangeError('CLIENT_INVALID_OPTION', 'shardId', 'less than shardCount');
     }
     if (typeof options.messageCacheMaxSize !== 'number' || isNaN(options.messageCacheMaxSize)) {
-      throw new TypeError('The messageCacheMaxSize option must be a number.');
+      throw new TypeError('CLIENT_INVALID_OPTION', 'messageCacheMaxSize', 'a number');
     }
     if (typeof options.messageCacheLifetime !== 'number' || isNaN(options.messageCacheLifetime)) {
-      throw new TypeError('The messageCacheLifetime option must be a number.');
+      throw new TypeError('CLIENT_INVALID_OPTION', 'The messageCacheLifetime', 'a number');
     }
     if (typeof options.messageSweepInterval !== 'number' || isNaN(options.messageSweepInterval)) {
-      throw new TypeError('The messageSweepInterval option must be a number.');
+      throw new TypeError('CLIENT_INVALID_OPTION', 'messageSweepInterval', 'a number');
     }
     if (typeof options.fetchAllMembers !== 'boolean') {
-      throw new TypeError('The fetchAllMembers option must be a boolean.');
+      throw new TypeError('CLIENT_INVALID_OPTION', 'fetchAllMembers', 'a boolean');
     }
     if (typeof options.disableEveryone !== 'boolean') {
-      throw new TypeError('The disableEveryone option must be a boolean.');
+      throw new TypeError('CLIENT_INVALID_OPTION', 'disableEveryone', 'a boolean');
     }
     if (typeof options.restWsBridgeTimeout !== 'number' || isNaN(options.restWsBridgeTimeout)) {
-      throw new TypeError('The restWsBridgeTimeout option must be a number.');
+      throw new TypeError('CLIENT_INVALID_OPTION', 'restWsBridgeTimeout', 'a number');
     }
     if (typeof options.internalSharding !== 'boolean') {
-      throw new TypeError('The internalSharding option must be a boolean.');
+      throw new TypeError('CLIENT_INVALID_OPTION', 'internalSharding', 'a boolean');
     }
-    if (options.internalSharding && ('shardCount' in options || 'shardId' in options)) {
-      throw new TypeError('You cannot specify shardCount/shardId if you are using internal sharding.');
+    if (!(options.disabledEvents instanceof Array)) {
+      throw new TypeError('CLIENT_INVALID_OPTION', 'disabledEvents', 'an Array');
     }
-    if (!(options.disabledEvents instanceof Array)) throw new TypeError('The disabledEvents option must be an Array.');
   }
 }
 
diff --git a/src/client/ClientDataResolver.js b/src/client/ClientDataResolver.js
index 1c268b73d..4de4c7dee 100644
--- a/src/client/ClientDataResolver.js
+++ b/src/client/ClientDataResolver.js
@@ -10,6 +10,7 @@ const Channel = require('../structures/Channel');
 const GuildMember = require('../structures/GuildMember');
 const Emoji = require('../structures/Emoji');
 const ReactionEmoji = require('../structures/ReactionEmoji');
+const { Error, TypeError } = require('../errors');
 
 /**
  * The DataResolver identifies different objects and tries to resolve a specific piece of information from them, e.g.
@@ -194,14 +195,14 @@ class ClientDataResolver {
           snekfetch.get(resource)
           .end((err, res) => {
             if (err) return reject(err);
-            if (!(res.body instanceof Buffer)) return reject(new TypeError('The response body isn\'t a Buffer.'));
+            if (!(res.body instanceof Buffer)) return reject(new TypeError('REQ_BODY_TYPE'));
             return resolve(res.body);
           });
         } else {
           const file = path.resolve(resource);
           fs.stat(file, (err, stats) => {
             if (err) return reject(err);
-            if (!stats || !stats.isFile()) return reject(new Error(`The file could not be found: ${file}`));
+            if (!stats || !stats.isFile()) return reject(new Error('FILE_NOT_FOUND', file));
             fs.readFile(file, (err2, data) => {
               if (err2) reject(err2); else resolve(data);
             });
@@ -211,7 +212,7 @@ class ClientDataResolver {
       });
     }
 
-    return Promise.reject(new TypeError('The resource must be a string or Buffer.'));
+    return Promise.reject(new TypeError('REQ_RESOURCE_TYPE'));
   }
 
   /**
diff --git a/src/client/ClientManager.js b/src/client/ClientManager.js
index 4239e2e4a..4b7f0102b 100644
--- a/src/client/ClientManager.js
+++ b/src/client/ClientManager.js
@@ -1,5 +1,6 @@
 const Constants = require('../util/Constants');
 const WebSocketConnection = require('./websocket/WebSocketConnection');
+const { Error } = require('../errors');
 
 /**
  * Manages the state and background tasks of the client.
@@ -37,16 +38,16 @@ class ClientManager {
   connectToWebSocket(token, resolve, reject) {
     this.client.emit(Constants.Events.DEBUG, `Authenticated using token ${token}`);
     this.client.token = token;
-    const timeout = this.client.setTimeout(() => reject(new Error(Constants.Errors.TOOK_TOO_LONG)), 1000 * 300);
+    const timeout = this.client.setTimeout(() => reject(new Error('INVALID_TOKEN')), 1000 * 300);
     this.client.api.gateway.get().then(res => {
       const protocolVersion = Constants.DefaultOptions.ws.version;
       const gateway = `${res.url}/?v=${protocolVersion}&encoding=${WebSocketConnection.ENCODING}`;
       this.client.emit(Constants.Events.DEBUG, `Using gateway ${gateway}`);
       this.client.ws.connect(gateway);
       this.client.ws.connection.once('close', event => {
-        if (event.code === 4004) reject(new Error(Constants.Errors.BAD_LOGIN));
-        if (event.code === 4010) reject(new Error(Constants.Errors.INVALID_SHARD));
-        if (event.code === 4011) reject(new Error(Constants.Errors.SHARDING_REQUIRED));
+        if (event.code === 4004) reject(new Error('TOKEN_INVALID'));
+        if (event.code === 4010) reject(new Error('SHARDING_INVALID'));
+        if (event.code === 4011) reject(new Error('SHARDING_REQUIRED'));
       });
       this.client.once(Constants.Events.READY, () => {
         resolve(token);
diff --git a/src/client/rest/APIRequest.js b/src/client/rest/APIRequest.js
index 5f21f25dc..a96249a7a 100644
--- a/src/client/rest/APIRequest.js
+++ b/src/client/rest/APIRequest.js
@@ -1,6 +1,6 @@
 const querystring = require('querystring');
 const snekfetch = require('snekfetch');
-const Constants = require('../../util/Constants');
+const { Error } = require('../../errors');
 
 class APIRequest {
   constructor(rest, method, path, options) {
@@ -28,7 +28,7 @@ class APIRequest {
     } else if (this.client.token) {
       return this.client.token;
     }
-    throw new Error(Constants.Errors.NO_TOKEN);
+    throw new Error('TOKEN_MISSING');
   }
 
   gen() {
diff --git a/src/client/rest/RESTManager.js b/src/client/rest/RESTManager.js
index 5a7e9f0ed..ca060b3b9 100644
--- a/src/client/rest/RESTManager.js
+++ b/src/client/rest/RESTManager.js
@@ -3,7 +3,7 @@ const SequentialRequestHandler = require('./RequestHandlers/Sequential');
 const BurstRequestHandler = require('./RequestHandlers/Burst');
 const APIRequest = require('./APIRequest');
 const mountApi = require('./APIRouter');
-const Constants = require('../../util/Constants');
+const { Error } = require('../../errors');
 
 class RESTManager {
   constructor(client) {
@@ -39,7 +39,7 @@ class RESTManager {
       case 'burst':
         return BurstRequestHandler;
       default:
-        throw new Error(Constants.Errors.INVALID_RATE_LIMIT_METHOD);
+        throw new Error('RATELIMIT_INVALID_METHOD');
     }
   }
 
diff --git a/src/client/voice/ClientVoiceManager.js b/src/client/voice/ClientVoiceManager.js
index a6a95eee9..400a752cc 100644
--- a/src/client/voice/ClientVoiceManager.js
+++ b/src/client/voice/ClientVoiceManager.js
@@ -1,5 +1,6 @@
 const Collection = require('../../util/Collection');
 const VoiceConnection = require('./VoiceConnection');
+const { Error } = require('../../errors');
 
 /**
  * Manages all the voice stuff for the client.
@@ -44,11 +45,7 @@ class ClientVoiceManager {
   joinChannel(channel) {
     return new Promise((resolve, reject) => {
       if (!channel.joinable) {
-        if (channel.full) {
-          throw new Error('You do not have permission to join this voice channel; it is full.');
-        } else {
-          throw new Error('You do not have permission to join this voice channel.');
-        }
+        throw new Error('VOICE_JOIN_CHANNEL', channel.full);
       }
 
       let connection = this.connections.get(channel.guild.id);
diff --git a/src/client/voice/VoiceConnection.js b/src/client/voice/VoiceConnection.js
index ff218623f..0c4af468c 100644
--- a/src/client/voice/VoiceConnection.js
+++ b/src/client/voice/VoiceConnection.js
@@ -6,6 +6,7 @@ const AudioPlayer = require('./player/AudioPlayer');
 const VoiceReceiver = require('./receiver/VoiceReceiver');
 const EventEmitter = require('events').EventEmitter;
 const Prism = require('prism-media');
+const { Error } = require('../../errors');
 
 /**
  * Represents a connection to a guild's voice server.
@@ -341,8 +342,8 @@ class VoiceConnection extends EventEmitter {
    */
   connect() {
     if (this.status !== Constants.VoiceStatus.RECONNECTING) {
-      if (this.sockets.ws) throw new Error('There is already an existing WebSocket connection.');
-      if (this.sockets.udp) throw new Error('There is already an existing UDP connection.');
+      if (this.sockets.ws) throw new Error('WS_CONNECTION_EXISTS');
+      if (this.sockets.udp) throw new Error('UDP_CONNECTION_EXISTS');
     }
 
     if (this.sockets.ws) this.sockets.ws.shutdown();
diff --git a/src/client/voice/VoiceUDPClient.js b/src/client/voice/VoiceUDPClient.js
index 0e148b754..6e12d5e7b 100644
--- a/src/client/voice/VoiceUDPClient.js
+++ b/src/client/voice/VoiceUDPClient.js
@@ -2,6 +2,7 @@ const udp = require('dgram');
 const dns = require('dns');
 const Constants = require('../../util/Constants');
 const EventEmitter = require('events').EventEmitter;
+const { Error } = require('../../errors');
 
 /**
  * Represents a UDP client for a Voice Connection.
@@ -89,8 +90,8 @@ class VoiceConnectionUDPClient extends EventEmitter {
    */
   send(packet) {
     return new Promise((resolve, reject) => {
-      if (!this.socket) throw new Error('Tried to send a UDP packet, but there is no socket available.');
-      if (!this.discordAddress || !this.discordPort) throw new Error('Malformed UDP address or port.');
+      if (!this.socket) throw new Error('UDP_SEND_FAIL');
+      if (!this.discordAddress || !this.discordPort) throw new Error('UDP_ADDRESS_MALFORMED');
       this.socket.send(packet, 0, packet.length, this.discordPort, this.discordAddress, error => {
         if (error) reject(error); else resolve(packet);
       });
diff --git a/src/client/voice/VoiceWebSocket.js b/src/client/voice/VoiceWebSocket.js
index 9179232fe..025c23ecc 100644
--- a/src/client/voice/VoiceWebSocket.js
+++ b/src/client/voice/VoiceWebSocket.js
@@ -1,6 +1,7 @@
 const Constants = require('../../util/Constants');
 const SecretKey = require('./util/SecretKey');
 const EventEmitter = require('events').EventEmitter;
+const { Error } = require('../../errors');
 
 let WebSocket;
 try {
@@ -88,9 +89,7 @@ class VoiceWebSocket extends EventEmitter {
    */
   send(data) {
     return new Promise((resolve, reject) => {
-      if (!this.ws || this.ws.readyState !== WebSocket.OPEN) {
-        throw new Error(`Voice websocket not open to send ${data}.`);
-      }
+      if (!this.ws || this.ws.readyState !== WebSocket.OPEN) throw new Error('WS_NOT_OPEN', data);
       this.ws.send(data, null, error => {
         if (error) reject(error); else resolve(data);
       });
diff --git a/src/client/voice/opus/OpusEngineList.js b/src/client/voice/opus/OpusEngineList.js
index 152481745..9ff9ad7bf 100644
--- a/src/client/voice/opus/OpusEngineList.js
+++ b/src/client/voice/opus/OpusEngineList.js
@@ -1,3 +1,5 @@
+const { Error } = require('../../../errors');
+
 const list = [
   require('./NodeOpusEngine'),
   require('./OpusScriptEngine'),
@@ -30,5 +32,5 @@ exports.fetch = engineOptions => {
 
 exports.guaranteeOpusEngine = () => {
   if (typeof opusEngineFound === 'undefined') opusEngineFound = Boolean(exports.fetch());
-  if (!opusEngineFound) throw new Error('Couldn\'t find an Opus engine.');
+  if (!opusEngineFound) throw new Error('OPUS_ENGINE_MISSING');
 };
diff --git a/src/client/voice/receiver/VoiceReceiver.js b/src/client/voice/receiver/VoiceReceiver.js
index 7b1b6c8e0..e57a39d9c 100644
--- a/src/client/voice/receiver/VoiceReceiver.js
+++ b/src/client/voice/receiver/VoiceReceiver.js
@@ -2,6 +2,7 @@ const EventEmitter = require('events').EventEmitter;
 const secretbox = require('../util/Secretbox');
 const Readable = require('./VoiceReadable');
 const OpusEncoders = require('../opus/OpusEngineList');
+const { Error } = require('../../../errors');
 
 const nonce = Buffer.alloc(24);
 nonce.fill(0);
@@ -122,8 +123,8 @@ class VoiceReceiver extends EventEmitter {
    */
   createOpusStream(user) {
     user = this.voiceConnection.voiceManager.client.resolver.resolveUser(user);
-    if (!user) throw new Error('Couldn\'t resolve the user to create Opus stream.');
-    if (this.opusStreams.get(user.id)) throw new Error('There is already an existing stream for that user.');
+    if (!user) throw new Error('VOICE_USER_MISSING');
+    if (this.opusStreams.get(user.id)) throw new Error('VOICE_STREAM_EXISTS');
     const stream = new Readable();
     this.opusStreams.set(user.id, stream);
     return stream;
@@ -137,8 +138,8 @@ class VoiceReceiver extends EventEmitter {
    */
   createPCMStream(user) {
     user = this.voiceConnection.voiceManager.client.resolver.resolveUser(user);
-    if (!user) throw new Error('Couldn\'t resolve the user to create PCM stream.');
-    if (this.pcmStreams.get(user.id)) throw new Error('There is already an existing stream for that user.');
+    if (!user) throw new Error('VOICE_USER_MISSING');
+    if (this.pcmStreams.get(user.id)) throw new Error('VOICE_STREAM_EXISTS');
     const stream = new Readable();
     this.pcmStreams.set(user.id, stream);
     return stream;
diff --git a/src/errors/DJSError.js b/src/errors/DJSError.js
new file mode 100644
index 000000000..b922b711d
--- /dev/null
+++ b/src/errors/DJSError.js
@@ -0,0 +1,65 @@
+// Heavily inspired by node's `internal/errors` module
+
+const kCode = Symbol('code');
+const messages = new Map();
+const assert = require('assert');
+const util = require('util');
+
+/**
+ * Extend an error of some sort into a DiscordjsError
+ * @param {Error} Base Base error to extend
+ * @returns {DiscordjsError}
+ */
+function makeDiscordjsError(Base) {
+  return class DiscordjsError extends Base {
+    constructor(key, ...args) {
+      super(message(key, args));
+      this[kCode] = key;
+      if (Error.captureStackTrace) Error.captureStackTrace(this, DiscordjsError);
+    }
+
+    get name() {
+      return `${super.name} [${this[kCode]}]`;
+    }
+
+    get code() {
+      return this[kCode];
+    }
+  };
+}
+
+/**
+ * Format the message for an error
+ * @param {string} key Error key
+ * @param {Array<*>} args Arguments to pass for util format or as function args
+ * @returns {string} Formatted string
+ */
+function message(key, args) {
+  assert.strictEqual(typeof key, 'string');
+  const msg = messages.get(key);
+  assert(msg, `An invalid error message key was used: ${key}.`);
+  let fmt = util.format;
+  if (typeof msg === 'function') {
+    fmt = msg;
+  } else {
+    if (args === undefined || args.length === 0) return msg;
+    args.unshift(msg);
+  }
+  return String(fmt(...args));
+}
+
+/**
+ * Register an error code and message
+ * @param {string} sym Unique name for the error
+ * @param {*} val Value of the error
+ */
+function register(sym, val) {
+  messages.set(sym, typeof val === 'function' ? val : String(val));
+}
+
+module.exports = {
+  register,
+  Error: makeDiscordjsError(Error),
+  TypeError: makeDiscordjsError(TypeError),
+  RangeError: makeDiscordjsError(RangeError),
+};
diff --git a/src/errors/Messages.js b/src/errors/Messages.js
new file mode 100644
index 000000000..ffaaec720
--- /dev/null
+++ b/src/errors/Messages.js
@@ -0,0 +1,84 @@
+const { register } = require('./DJSError');
+
+const Messages = {
+  CLIENT_INVALID_OPTION: (prop, must) => `The ${prop} option must be ${must}`,
+
+  TOKEN_INVALID: 'An invalid token was provided.',
+  TOKEN_MISSING: 'Request to use token, but token was unavailable to the client.',
+
+  FEATURE_BOT_ONLY: 'Only bot accounts are able to make use of this feature.',
+  FEATURE_USER_ONLY: 'Only user accounts are able to make use of this feature.',
+
+  WS_BAD_MESSAGE: 'A bad message was received from the websocket; either bad compression, or not JSON.',
+  WS_CONNECTION_EXISTS: 'There is already an existing WebSocket connection.',
+  WS_NOT_OPEN: (data = 'data') => `Websocket not open to send ${data}`,
+
+  PERMISSIONS_INVALID: 'Invalid permission string or number.',
+  PERMISSIONS_INVALID_FLAG: 'Invalid bitfield flag string or number',
+
+  RATELIMIT_INVALID_METHOD: 'Unknown rate limiting method.',
+
+  SHARDING_INVALID: 'Invalid shard settings were provided.',
+  SHARDING_REQUIRED: 'This session would have handled too many guilds - Sharding is required.',
+  SHARDING_CHILD_CONNECTION: 'Failed to send message to shard\'s process.',
+  SHARDING_PARENT_CONNECTION: 'Failed to send message to master process.',
+  SHARDING_NO_SHARDS: 'No shards have been spawned',
+  SHARDING_IN_PROCESS: 'Shards are still being spawned',
+  SHARDING_ALREADY_SPAWNED: count => `Already spawned ${count} shards`,
+
+  COLOR_RANGE: 'Color must be within the range 0 - 16777215 (0xFFFFFF).',
+  COLOR_CONVERT: 'Unable to convert color to a number.',
+
+  EMBED_FIELD_COUNT: 'MessageEmbeds may not exceed 25 fields.',
+  EMBED_FIELD_NAME: 'MessageEmbed field names may not exceed 256 characters or be empty.',
+  EMBED_FIELD_VALUE: 'MessageEmbed field values may not exceed 1024 characters or be empty.',
+  EMBED_FILE_LIMIT: 'You may not upload more than one file at once.',
+  EMBED_DESCRIPTION: 'MessageEmbed descriptions may not exceed 2048 characters.',
+  EMBED_FOOTER_TEXT: 'MessageEmbed footer text may not exceed 2048 characters.',
+  EMBED_TITLE: 'MessageEmbed titles may not exceed 256 characters.',
+
+  FILE_NOT_FOUND: file => `File could not be found: ${file}`,
+
+  USER_STATUS: 'User status must be a string',
+  SHARD_MESSAGE_FAILED: 'Failed to send message to master process.',
+
+  VOICE_INVALID_HEARTBEAT: 'Tried to set voice heartbeat but no valid interval was specified.',
+  VOICE_USER_MISSING: 'Couldn\'t resolve the user to create stream.',
+  VOICE_STREAM_EXISTS: 'There is already an existing stream for that user.',
+  VOICE_JOIN_CHANNEL: (full = false) =>
+    `You do not have permission to join this voice channel${full ? '; it is full.' : '.'}`,
+
+  OPUS_ENGINE_MISSING: 'Couldn\'t find an Opus engine.',
+
+  UDP_SEND_FAIL: 'Tried to send a UDP packet, but there is no socket available.',
+  UDP_ADDRESS_MALFORMED: 'Malformed UDP address or port.',
+  UDP_CONNECTION_EXISTS: 'There is already an existing UDP connection.',
+
+  REQ_BODY_TYPE: 'The response body isn\'t a Buffer.',
+  REQ_RESOURCE_TYPE: 'The resource must be a string or Buffer.',
+
+  IMAGE_FORMAT: format => `Invalid image format: ${format}`,
+  IMAGE_SIZE: size => `Invalid image size: ${size}`,
+
+  MESSAGE_MISSING: 'Message not found',
+  MESSAGE_BULK_DELETE_TYPE: 'The messages must be an Array, Collection, or number.',
+  MESSAGE_NONCE_TYPE: 'Message nonce must fit in an unsigned 64-bit integer.',
+
+  TYPING_COUNT: 'Count must be at least 1',
+
+  SPLIT_MAX_LEN: 'Message exceeds the max length and contains no split characters.',
+
+  BAN_RESOLVE_ID: 'Couldn\'t resolve the user ID to unban.',
+
+  PRUNE_DAYS_TYPE: 'Days must be a number',
+
+  SEARCH_CHANNEL_TYPE: 'Target must be a TextChannel, DMChannel, GroupDMChannel, or Guild.',
+
+  MESSAGE_SPLIT_MISSING: 'Message exceeds the max length and contains no split characters.',
+
+  GUILD_CHANNEL_RESOLVE: 'Could not resolve channel to a guild channel.',
+
+  EMOJI_TYPE: 'Emoji must be a string or Emoji/ReactionEmoji',
+};
+
+for (const [name, message] of Object.entries(Messages)) register(name, message);
diff --git a/src/errors/index.js b/src/errors/index.js
new file mode 100644
index 000000000..39b7582df
--- /dev/null
+++ b/src/errors/index.js
@@ -0,0 +1,2 @@
+module.exports = require('./DJSError');
+module.exports.Messages = require('./Messages');
diff --git a/src/sharding/Shard.js b/src/sharding/Shard.js
index a73447b85..f0cc51098 100644
--- a/src/sharding/Shard.js
+++ b/src/sharding/Shard.js
@@ -1,6 +1,7 @@
 const childProcess = require('child_process');
 const path = require('path');
 const Util = require('../util/Util');
+const { Error } = require('../errors');
 
 /**
  * Represents a Shard spawned by the ShardingManager.
@@ -60,7 +61,7 @@ class Shard {
       const sent = this.process.send(message, err => {
         if (err) reject(err); else resolve(this);
       });
-      if (!sent) throw new Error('Failed to send message to shard\'s process.');
+      if (!sent) throw new Error('SHARDING_CHILD_CONNECTION');
     });
   }
 
diff --git a/src/sharding/ShardClientUtil.js b/src/sharding/ShardClientUtil.js
index b41deb5d1..549353df2 100644
--- a/src/sharding/ShardClientUtil.js
+++ b/src/sharding/ShardClientUtil.js
@@ -1,4 +1,5 @@
 const Util = require('../util/Util');
+const { Error } = require('../errors');
 
 /**
  * Helper class for sharded clients spawned as a child process, such as from a ShardingManager.
@@ -40,7 +41,7 @@ class ShardClientUtil {
       const sent = process.send(message, err => {
         if (err) reject(err); else resolve();
       });
-      if (!sent) throw new Error('Failed to send message to master process.');
+      if (!sent) throw new Error('SHARDING_PARENT_CONNECTION');
     });
   }
 
diff --git a/src/sharding/ShardingManager.js b/src/sharding/ShardingManager.js
index e105f3e3f..bfae42f22 100644
--- a/src/sharding/ShardingManager.js
+++ b/src/sharding/ShardingManager.js
@@ -4,6 +4,7 @@ const EventEmitter = require('events').EventEmitter;
 const Shard = require('./Shard');
 const Collection = require('../util/Collection');
 const Util = require('../util/Util');
+const { Error, TypeError, RangeError } = require('../errors');
 
 /**
  * This is a utility class that can be used to help you spawn shards of your client. Each shard is completely separate
@@ -34,10 +35,10 @@ class ShardingManager extends EventEmitter {
      * @type {string}
      */
     this.file = file;
-    if (!file) throw new Error('File must be specified.');
+    if (!file) throw new Error('CLIENT_INVALID_OPTION', 'File', 'specified.');
     if (!path.isAbsolute(file)) this.file = path.resolve(process.cwd(), file);
     const stats = fs.statSync(this.file);
-    if (!stats.isFile()) throw new Error('File path does not point to a file.');
+    if (!stats.isFile()) throw new Error('CLIENT_INVALID_OPTION', 'File', 'a file');
 
     /**
      * Amount of shards that this manager is going to spawn
@@ -46,11 +47,11 @@ class ShardingManager extends EventEmitter {
     this.totalShards = options.totalShards;
     if (this.totalShards !== 'auto') {
       if (typeof this.totalShards !== 'number' || isNaN(this.totalShards)) {
-        throw new TypeError('Amount of shards must be a number.');
+        throw new TypeError('CLIENT_INVALID_OPTION', 'Amount of shards', 'a number.');
       }
-      if (this.totalShards < 1) throw new RangeError('Amount of shards must be at least 1.');
+      if (this.totalShards < 1) throw new RangeError('CLIENT_INVALID_OPTION', 'Amount of shards', 'at least 1.');
       if (this.totalShards !== Math.floor(this.totalShards)) {
-        throw new RangeError('Amount of shards must be an integer.');
+        throw new RangeError('CLIENT_INVALID_OPTION', 'Amount of shards', 'an integer.');
       }
     }
 
@@ -109,9 +110,13 @@ class ShardingManager extends EventEmitter {
         return this._spawn(count, delay);
       });
     } else {
-      if (typeof amount !== 'number' || isNaN(amount)) throw new TypeError('Amount of shards must be a number.');
-      if (amount < 1) throw new RangeError('Amount of shards must be at least 1.');
-      if (amount !== Math.floor(amount)) throw new TypeError('Amount of shards must be an integer.');
+      if (typeof amount !== 'number' || isNaN(amount)) {
+        throw new TypeError('CLIENT_INVALID_OPTION', 'Amount of shards', 'a number.');
+      }
+      if (amount < 1) throw new RangeError('CLIENT_INVALID_OPTION', 'Amount of shards', 'at least 1.');
+      if (amount !== Math.floor(amount)) {
+        throw new TypeError('CLIENT_INVALID_OPTION', 'Amount of shards', 'an integer.');
+      }
       return this._spawn(amount, delay);
     }
   }
@@ -125,7 +130,7 @@ class ShardingManager extends EventEmitter {
    */
   _spawn(amount, delay) {
     return new Promise(resolve => {
-      if (this.shards.size >= amount) throw new Error(`Already spawned ${this.shards.size} shards.`);
+      if (this.shards.size >= amount) throw new Error('SHARDING_ALREADY_SPAWNED', this.shards.size);
       this.totalShards = amount;
 
       this.createShard();
@@ -181,8 +186,8 @@ class ShardingManager extends EventEmitter {
    * }).catch(console.error);
    */
   fetchClientValues(prop) {
-    if (this.shards.size === 0) return Promise.reject(new Error('No shards have been spawned.'));
-    if (this.shards.size !== this.totalShards) return Promise.reject(new Error('Still spawning shards.'));
+    if (this.shards.size === 0) return Promise.reject(new Error('SHARDING_NO_SHARDS'));
+    if (this.shards.size !== this.totalShards) return Promise.reject(new Error('SHARDING_IN_PROCESS'));
     const promises = [];
     for (const shard of this.shards.values()) promises.push(shard.fetchClientValue(prop));
     return Promise.all(promises);
diff --git a/src/structures/ClientUser.js b/src/structures/ClientUser.js
index cd04ad8f3..e0a2f3ba2 100644
--- a/src/structures/ClientUser.js
+++ b/src/structures/ClientUser.js
@@ -6,6 +6,7 @@ const Util = require('../util/Util');
 const Guild = require('./Guild');
 const Message = require('./Message');
 const GroupDMChannel = require('./GroupDMChannel');
+const { TypeError } = require('../errors');
 
 /**
  * Represents the logged in client's Discord user.
@@ -193,7 +194,7 @@ class ClientUser extends User {
       }
 
       if (data.status) {
-        if (typeof data.status !== 'string') throw new TypeError('Status must be a string');
+        if (typeof data.status !== 'string') throw new TypeError('STATUS_TYPE');
         if (this.bot) {
           status = data.status;
         } else {
diff --git a/src/structures/Guild.js b/src/structures/Guild.js
index 3b6f0d9ef..2dd62514a 100644
--- a/src/structures/Guild.js
+++ b/src/structures/Guild.js
@@ -14,6 +14,7 @@ const Util = require('../util/Util');
 const Snowflake = require('../util/Snowflake');
 const Permissions = require('../util/Permissions');
 const Shared = require('./shared');
+const { Error, TypeError } = require('../errors');
 
 /**
  * Represents a guild (or a server) on Discord.
@@ -804,8 +805,7 @@ class Guild {
    */
   unban(user, reason) {
     const id = this.client.resolver.resolveUserID(user);
-    if (!id) throw new Error('Couldn\'t resolve the user ID to unban.');
-
+    if (!id) throw new Error('BAN_RESOLVE_ID');
     return this.client.api.guilds(this.id).bans(id).delete({ reason })
       .then(() => user);
   }
@@ -828,7 +828,7 @@ class Guild {
    *   .catch(console.error);
    */
   pruneMembers({ days = 7, dry = false, reason } = {}) {
-    if (typeof days !== 'number') throw new TypeError('Days must be a number.');
+    if (typeof days !== 'number') throw new TypeError('PRUNE_DAYS_TYPE');
     return this.client.api.guilds(this.id).prune[dry ? 'get' : 'post']({ query: { days }, reason })
       .then(data => data.pruned);
   }
diff --git a/src/structures/GuildMember.js b/src/structures/GuildMember.js
index 201a2b792..92969e493 100644
--- a/src/structures/GuildMember.js
+++ b/src/structures/GuildMember.js
@@ -3,6 +3,7 @@ const Role = require('./Role');
 const Permissions = require('../util/Permissions');
 const Collection = require('../util/Collection');
 const Presence = require('./Presence').Presence;
+const { Error } = require('../errors');
 
 /**
  * Represents a member of a guild on Discord.
@@ -287,7 +288,7 @@ class GuildMember {
    */
   permissionsIn(channel) {
     channel = this.client.resolver.resolveChannel(channel);
-    if (!channel || !channel.guild) throw new Error('Could not resolve channel to a guild channel.');
+    if (!channel || !channel.guild) throw new Error('GUILD_CHANNEL_RESOLVE');
     return channel.permissionsFor(this);
   }
 
diff --git a/src/structures/Message.js b/src/structures/Message.js
index 84bafec68..d4b7f001c 100644
--- a/src/structures/Message.js
+++ b/src/structures/Message.js
@@ -7,6 +7,7 @@ const Util = require('../util/Util');
 const Collection = require('../util/Collection');
 const Constants = require('../util/Constants');
 const Permissions = require('../util/Permissions');
+const { TypeError } = require('../errors');
 let GuildMember;
 
 /**
@@ -428,7 +429,7 @@ class Message {
    */
   react(emoji) {
     emoji = this.client.resolver.resolveEmojiIdentifier(emoji);
-    if (!emoji) throw new TypeError('Emoji must be a string or Emoji/ReactionEmoji');
+    if (!emoji) throw new TypeError('EMOJI_TYPE');
 
     return this.client.api.channels(this.channel.id).messages(this.id).reactions(emoji)['@me']
       .put()
diff --git a/src/structures/MessageEmbed.js b/src/structures/MessageEmbed.js
index 35d222b1c..21ef03c68 100644
--- a/src/structures/MessageEmbed.js
+++ b/src/structures/MessageEmbed.js
@@ -1,4 +1,5 @@
 const Util = require('../util/Util');
+const { RangeError } = require('../errors');
 
 /**
  * Represents an embed in a message (image/video preview, rich embed, etc.)
@@ -165,13 +166,11 @@ class MessageEmbed {
    * @returns {MessageEmbed} This embed
    */
   addField(name, value, inline = false) {
-    if (this.fields.length >= 25) throw new RangeError('MessageEmbeds may not exceed 25 fields.');
+    if (this.fields.length >= 25) throw new RangeError('EMBED_FIELD_COUNT');
     name = Util.resolveString(name);
-    if (name.length > 256) throw new RangeError('MessageEmbed field names may not exceed 256 characters.');
-    if (!/\S/.test(name)) throw new RangeError('MessageEmbed field names may not be empty.');
+    if (!String(name) || name.length > 256) throw new RangeError('EMBED_FIELD_NAME');
     value = Util.resolveString(value);
-    if (value.length > 1024) throw new RangeError('MessageEmbed field values may not exceed 1024 characters.');
-    if (!/\S/.test(value)) throw new RangeError('MessageEmbed field values may not be empty.');
+    if (!String(name) || value.length > 1024) throw new RangeError('EMBED_FIELD_VALUE');
     this.fields.push({ name, value, inline });
     return this;
   }
@@ -183,7 +182,7 @@ class MessageEmbed {
    * @returns {MessageEmbed} This embed
    */
   attachFile(file) {
-    if (this.file) throw new RangeError('You may not upload more than one file at once.');
+    if (this.file) throw new RangeError('EMBED_FILE_LIMIT');
     this.file = file;
     return this;
   }
@@ -217,7 +216,7 @@ class MessageEmbed {
    */
   setDescription(description) {
     description = Util.resolveString(description);
-    if (description.length > 2048) throw new RangeError('MessageEmbed descriptions may not exceed 2048 characters.');
+    if (description.length > 2048) throw new RangeError('EMBED_DESCRIPTION');
     this.description = description;
     return this;
   }
@@ -230,7 +229,7 @@ class MessageEmbed {
    */
   setFooter(text, iconURL) {
     text = Util.resolveString(text);
-    if (text.length > 2048) throw new RangeError('MessageEmbed footer text may not exceed 2048 characters.');
+    if (text.length > 2048) throw new RangeError('EMBED_FOOTER_TEXT');
     this.footer = { text, iconURL };
     return this;
   }
@@ -272,7 +271,7 @@ class MessageEmbed {
    */
   setTitle(title) {
     title = Util.resolveString(title);
-    if (title.length > 256) throw new RangeError('MessageEmbed titles may not exceed 256 characters.');
+    if (title.length > 256) throw new RangeError('EMBED_TITLE');
     this.title = title;
     return this;
   }
diff --git a/src/structures/interfaces/TextBasedChannel.js b/src/structures/interfaces/TextBasedChannel.js
index 5d4957ded..08b745dda 100644
--- a/src/structures/interfaces/TextBasedChannel.js
+++ b/src/structures/interfaces/TextBasedChannel.js
@@ -3,6 +3,7 @@ const MessageCollector = require('../MessageCollector');
 const Shared = require('../shared');
 const Collection = require('../../util/Collection');
 const Snowflake = require('../../util/Snowflake');
+const { Error, RangeError, TypeError } = require('../../errors');
 
 /**
  * Interface for classes that have text-channel-like features.
@@ -136,7 +137,7 @@ class TextBasedChannel {
       return this.fetchMessages({ limit: 1, around: messageID })
       .then(messages => {
         const msg = messages.get(messageID);
-        if (!msg) throw new Error('Message not found.');
+        if (!msg) throw new Error('MESSAGE_MISSING');
         return msg;
       });
     }
@@ -227,7 +228,7 @@ class TextBasedChannel {
    * channel.startTyping();
    */
   startTyping(count) {
-    if (typeof count !== 'undefined' && count < 1) throw new RangeError('Count must be at least 1.');
+    if (typeof count !== 'undefined' && count < 1) throw new RangeError('TYPING_COUNT');
     if (!this.client.user._typing.has(this.id)) {
       const endpoint = this.client.api.channels(this.id).typing;
       this.client.user._typing.set(this.id, {
@@ -361,7 +362,7 @@ class TextBasedChannel {
         }).messages
       );
     }
-    throw new TypeError('The messages must be an Array, Collection, or number.');
+    throw new TypeError('MESSAGE_BULK_DELETE_TYPE');
   }
 
   /**
diff --git a/src/structures/shared/Search.js b/src/structures/shared/Search.js
index 63606f5c9..76ed72eef 100644
--- a/src/structures/shared/Search.js
+++ b/src/structures/shared/Search.js
@@ -1,4 +1,5 @@
 const long = require('long');
+const { TypeError } = require('../../errors');
 
 /**
  * @typedef {Object} MessageSearchOptions
@@ -84,9 +85,7 @@ module.exports = function search(target, options) {
   const Guild = require('../Guild');
   const Message = require('../Message');
 
-  if (!(target instanceof Channel || target instanceof Guild)) {
-    throw new TypeError('Target must be a TextChannel, DMChannel, GroupDMChannel, or Guild.');
-  }
+  if (!(target instanceof Channel || target instanceof Guild)) throw new TypeError('SEARCH_CHANNEL_TYPE');
 
   let endpoint = target.client.api[target instanceof Channel ? 'channels' : 'guilds'](target.id).messages().search;
   return endpoint.get({ query: options }).then(body => {
diff --git a/src/structures/shared/SendMessage.js b/src/structures/shared/SendMessage.js
index bd93e4dbe..d9e328e9d 100644
--- a/src/structures/shared/SendMessage.js
+++ b/src/structures/shared/SendMessage.js
@@ -1,4 +1,5 @@
 const Util = require('../../util/Util');
+const { RangeError } = require('../../errors');
 
 module.exports = function sendMessage(channel, options) {
   const User = require('../User');
@@ -8,7 +9,7 @@ module.exports = function sendMessage(channel, options) {
 
   if (typeof nonce !== 'undefined') {
     nonce = parseInt(nonce);
-    if (isNaN(nonce) || nonce < 0) throw new RangeError('Message nonce must fit in an unsigned 64-bit integer.');
+    if (isNaN(nonce) || nonce < 0) throw new RangeError('MESSAGE_NONCE_TYPE');
   }
 
   if (content) {
diff --git a/src/util/Constants.js b/src/util/Constants.js
index 98b359b4c..6da968eea 100644
--- a/src/util/Constants.js
+++ b/src/util/Constants.js
@@ -1,4 +1,5 @@
 exports.Package = require('../../package.json');
+const { Error, RangeError } = require('../errors');
 
 /**
  * Options for a client.
@@ -78,20 +79,6 @@ exports.WSCodes = {
   4011: 'Shard would be on too many guilds if connected',
 };
 
-exports.Errors = {
-  NO_TOKEN: 'Request to use token, but token was unavailable to the client.',
-  NO_BOT_ACCOUNT: 'Only bot accounts are able to make use of this feature.',
-  NO_USER_ACCOUNT: 'Only user accounts are able to make use of this feature.',
-  BAD_WS_MESSAGE: 'A bad message was received from the websocket; either bad compression, or not JSON.',
-  TOOK_TOO_LONG: 'Something took too long to do.',
-  NOT_A_PERMISSION: 'Invalid permission string or number.',
-  INVALID_RATE_LIMIT_METHOD: 'Unknown rate limiting method.',
-  BAD_LOGIN: 'Incorrect login details were provided.',
-  INVALID_SHARD: 'Invalid shard settings were provided.',
-  SHARDING_REQUIRED: 'This session would have handled too many guilds - Sharding is required.',
-  INVALID_TOKEN: 'An invalid token was provided.',
-};
-
 const AllowedImageFormats = [
   'webp',
   'png',
@@ -108,8 +95,8 @@ const AllowedImageSizes = [
 ];
 
 function checkImage({ size, format }) {
-  if (format && !AllowedImageFormats.includes(format)) throw new Error(`Invalid image format: ${format}`);
-  if (size && !AllowedImageSizes.includes(size)) throw new RangeError(`Invalid size: ${size}`);
+  if (format && !AllowedImageFormats.includes(format)) throw new Error('IMAGE_FORMAT', format);
+  if (size && !AllowedImageSizes.includes(size)) throw new RangeError('IMAGE_SIZE', size);
 }
 
 exports.Endpoints = {
diff --git a/src/util/Permissions.js b/src/util/Permissions.js
index 04b1864fd..b6dd20478 100644
--- a/src/util/Permissions.js
+++ b/src/util/Permissions.js
@@ -1,4 +1,4 @@
-const Constants = require('../util/Constants');
+const { RangeError } = require('../errors');
 
 /**
  * Data structure that makes it easy to interact with a permission bitfield. All {@link GuildMember}s have a set of
@@ -95,7 +95,7 @@ class Permissions {
   static resolve(permission) {
     if (permission instanceof Array) return permission.map(p => this.resolve(p)).reduce((prev, p) => prev | p, 0);
     if (typeof permission === 'string') permission = this.FLAGS[permission];
-    if (typeof permission !== 'number' || permission < 1) throw new RangeError(Constants.Errors.NOT_A_PERMISSION);
+    if (typeof permission !== 'number' || permission < 1) throw new RangeError('PERMISSION_INVALID');
     return permission;
   }
 }
diff --git a/src/util/Util.js b/src/util/Util.js
index e48d736c8..ef61cec5f 100644
--- a/src/util/Util.js
+++ b/src/util/Util.js
@@ -1,6 +1,7 @@
 const snekfetch = require('snekfetch');
 const Constants = require('./Constants');
 const ConstantsHttp = Constants.DefaultOptions.http;
+const { RangeError, TypeError } = require('../errors');
 
 /**
  * Contains various general-purpose utility methods. These functions are also available on the base `Discord` object.
@@ -19,7 +20,9 @@ class Util {
   static splitMessage(text, { maxLength = 1950, char = '\n', prepend = '', append = '' } = {}) {
     if (text.length <= maxLength) return text;
     const splitText = text.split(char);
-    if (splitText.length === 1) throw new Error('Message exceeds the max length and contains no split characters.');
+    if (splitText.length === 1) {
+      throw new RangeError('SPLIT_MAX_LEN');
+    }
     const messages = [''];
     let msg = 0;
     for (let i = 0; i < splitText.length; i++) {
@@ -54,7 +57,7 @@ class Util {
    */
   static fetchRecommendedShards(token, guildsPerShard = 1000) {
     return new Promise((resolve, reject) => {
-      if (!token) throw new Error('A token must be provided.');
+      if (!token) throw new Error('TOKEN_MISSING');
       snekfetch.get(`${ConstantsHttp.host}/api/v${ConstantsHttp.version}${Constants.Endpoints.botGateway}`)
         .set('Authorization', `Bot ${token.replace(/^Bot\s*/i, '')}`)
         .end((err, res) => {
@@ -279,9 +282,9 @@ class Util {
     }
 
     if (color < 0 || color > 0xFFFFFF) {
-      throw new RangeError('Color must be within the range 0 - 16777215 (0xFFFFFF).');
+      throw new RangeError('COLOR_RANGE');
     } else if (color && isNaN(color)) {
-      throw new TypeError('Unable to convert color to a number.');
+      throw new TypeError('COLOR_CONVERT');
     }
 
     return color;