diff --git a/src/structures/CategoryChannel.js b/src/structures/CategoryChannel.js
new file mode 100644
index 000000000..89b8b3165
--- /dev/null
+++ b/src/structures/CategoryChannel.js
@@ -0,0 +1,9 @@
+const GuildChannel = require('./GuildChannel');
+
+class CategoryChannel extends GuildChannel {
+  get children() {
+    return this.guild.channels.filter(c => c.parentID === this.id);
+  }
+}
+
+module.exports = CategoryChannel;
diff --git a/src/structures/Channel.js b/src/structures/Channel.js
index f70ec5bd8..ef21039f8 100644
--- a/src/structures/Channel.js
+++ b/src/structures/Channel.js
@@ -17,6 +17,7 @@ class Channel extends Base {
      * * `group` - a Group DM channel
      * * `text` - a guild text channel
      * * `voice` - a guild voice channel
+     * * `category` - a guild category channel
      * * `unknown` - a generic channel of unknown type, could be Channel or GuildChannel
      * @type {string}
      */
@@ -69,6 +70,7 @@ class Channel extends Base {
     const GroupDMChannel = require('./GroupDMChannel');
     const TextChannel = require('./TextChannel');
     const VoiceChannel = require('./VoiceChannel');
+    const CategoryChannel = require('./CategoryChannel');
     const GuildChannel = require('./GuildChannel');
     const types = Constants.ChannelTypes;
     let channel;
@@ -86,6 +88,9 @@ class Channel extends Base {
           case types.VOICE:
             channel = new VoiceChannel(guild, data);
             break;
+          case types.CATEGORY:
+            channel = new CategoryChannel(guild, data);
+            break;
           default:
             channel = new GuildChannel(guild, data);
         }
diff --git a/src/structures/Guild.js b/src/structures/Guild.js
index 8a4b8db21..4af91a5c7 100644
--- a/src/structures/Guild.js
+++ b/src/structures/Guild.js
@@ -891,10 +891,9 @@ class Guild extends Base {
   /**
    * Creates a new channel in the guild.
    * @param {string} name The name of the new channel
-   * @param {string} type The type of the new channel, either `text` or `voice`
-   * @param {Object} [options={}] Options
+   * @param {string} type The type of the new channel, either `text`, `voice`, or `category`
+   * @param {Object} [options] Options
    * @param {Array<PermissionOverwrites|ChannelCreationOverwrites>} [options.overwrites] Permission overwrites
-   * to apply to the new channel
    * @param {string} [options.reason] Reason for creating this channel
    * @returns {Promise<TextChannel|VoiceChannel>}
    * @example
@@ -1205,31 +1204,17 @@ class Guild extends Base {
 
   /**
    * Fetches a collection of channels in the current guild sorted by position.
-   * @param {string} type The channel type
+   * @param {Channel} channel Channel
    * @returns {Collection<Snowflake, GuildChannel>}
    * @private
    */
-  _sortedChannels(type) {
-    return this._sortPositionWithID(this.channels.filter(c => {
-      if (type === 'voice' && c.type === 'voice') return true;
-      else if (type !== 'voice' && c.type !== 'voice') return true;
-      else return type === c.type;
-    }));
-  }
-
-  /**
-   * Sorts a collection by object position or ID if the positions are equivalent.
-   * Intended to be identical to Discord's sorting method.
-   * @param {Collection} collection The collection to sort
-   * @returns {Collection}
-   * @private
-   */
-  _sortPositionWithID(collection) {
-    return collection.sort((a, b) =>
-      a.position !== b.position ?
-        a.position - b.position :
-        Long.fromString(a.id).sub(Long.fromString(b.id)).toNumber()
-    );
+  _sortedChannels(channel) {
+    const sort = col => col
+      .sort((a, b) => a.rawPosition - b.rawPosition || Long.fromString(a.id).sub(Long.fromString(b.id)).toNumber());
+    if (channel.type === Constants.ChannelTypes.CATEGORY) {
+      return sort(this.channels.filter(c => c.type === Constants.ChannelTypes.CATEGORY));
+    }
+    return sort(this.channels.filter(c => c.parent === channel.parent));
   }
 }
 
diff --git a/src/structures/GuildChannel.js b/src/structures/GuildChannel.js
index 195b40053..f45a5de48 100644
--- a/src/structures/GuildChannel.js
+++ b/src/structures/GuildChannel.js
@@ -2,6 +2,7 @@ const Channel = require('./Channel');
 const Role = require('./Role');
 const Invite = require('./Invite');
 const PermissionOverwrites = require('./PermissionOverwrites');
+const Util = require('../util/Util');
 const Permissions = require('../util/Permissions');
 const Collection = require('../util/Collection');
 const Constants = require('../util/Constants');
@@ -32,10 +33,16 @@ class GuildChannel extends Channel {
     this.name = data.name;
 
     /**
-     * The position of the channel in the list
+     * The raw position of the channel from discord
      * @type {number}
      */
-    this.position = data.position;
+    this.rawPosition = data.position;
+
+    /**
+     * The ID of the category parent of this channel
+     * @type {?Snowflake}
+     */
+    this.parentID = data.parent_id;
 
     /**
      * A map of permission overwrites in this channel for roles and users
@@ -49,13 +56,21 @@ class GuildChannel extends Channel {
     }
   }
 
+  /**
+   * The category parent of this channel
+   * @type {?GuildChannel}
+   */
+  get parent() {
+    return this.guild.channels.get(this.parentID);
+  }
+
   /**
    * The position of the channel
    * @type {number}
    * @readonly
    */
-  get calculatedPosition() {
-    const sorted = this.guild._sortedChannels(this.type);
+  get position() {
+    const sorted = this.guild._sortedChannels(this);
     return sorted.array().indexOf(sorted.get(this.id));
   }
 
@@ -70,34 +85,32 @@ class GuildChannel extends Channel {
     if (!member) return null;
     if (member.id === this.guild.ownerID) return new Permissions(Permissions.ALL);
 
-    let permissions = 0;
-
-    const roles = member.roles;
-    for (const role of roles.values()) permissions |= role.permissions;
-
-    const overwrites = this.overwritesFor(member, true, roles);
+    let resolved = this.guild.roles.get(this.guild.id).permissions;
 
+    const overwrites = this.overwritesFor(member, true);
     if (overwrites.everyone) {
-      permissions &= ~overwrites.everyone._denied;
-      permissions |= overwrites.everyone._allowed;
+      resolved &= ~overwrites.everyone._denied;
+      resolved |= overwrites.everyone._allowed;
     }
 
-    let allow = 0;
+    let allows = 0;
+    let denies = 0;
     for (const overwrite of overwrites.roles) {
-      permissions &= ~overwrite._denied;
-      allow |= overwrite._allowed;
+      allows |= overwrite._allowed;
+      denies |= overwrite._denied;
     }
-    permissions |= allow;
+    resolved &= ~denies;
+    resolved |= allows;
 
     if (overwrites.member) {
-      permissions &= ~overwrites.member._denied;
-      permissions |= overwrites.member._allowed;
+      resolved &= ~overwrites.member._denied;
+      resolved |= overwrites.member._allowed;
     }
 
-    const admin = Boolean(permissions & Permissions.FLAGS.ADMINISTRATOR);
-    if (admin) permissions = Permissions.ALL;
+    const admin = Boolean(resolved & Permissions.FLAGS.ADMINISTRATOR);
+    if (admin) resolved = Permissions.ALL;
 
-    return new Permissions(permissions);
+    return new Permissions(resolved);
   }
 
   overwritesFor(member, verified = false, roles = null) {
@@ -236,10 +249,12 @@ class GuildChannel extends Channel {
     return this.client.api.channels(this.id).patch({
       data: {
         name: (data.name || this.name).trim(),
-        topic: data.topic || this.topic,
+        topic: data.topic,
         position: data.position || this.position,
         bitrate: data.bitrate || (this.bitrate ? this.bitrate * 1000 : undefined),
-        user_limit: data.userLimit || this.userLimit,
+        user_limit: data.userLimit != null ? data.userLimit : this.userLimit, // eslint-disable-line eqeqeq
+        parent_id: data.parentID,
+        lock_permissions: data.lockPermissions,
       },
       reason,
     }).then(newData => {
@@ -275,8 +290,34 @@ class GuildChannel extends Channel {
    *   .then(newChannel => console.log(`Channel's new position is ${newChannel.position}`))
    *   .catch(console.error);
    */
-  setPosition(position, relative) {
-    return this.guild.setChannelPosition(this, position, relative).then(() => this);
+  setPosition(position, { relative, reason }) {
+    position = Number(position);
+    if (isNaN(position)) return Promise.reject(new TypeError('INVALID_TYPE', 'position', 'number'));
+    let updatedChannels = this.guild._sortedChannels(this).array();
+    Util.moveElementInArray(updatedChannels, this, position, relative);
+    updatedChannels = updatedChannels.map((r, i) => ({ id: r.id, position: i }));
+    return this.client.api.guilds(this.id).channels.patch({ data: updatedChannels, reason })
+      .then(() => {
+        this.client.actions.GuildChannelsPositionUpdate.handle({
+          guild_id: this.id,
+          channels: updatedChannels,
+        });
+        return this;
+      });
+  }
+
+  /**
+   * Set the category parent of this channel.
+   * @param {GuildChannel|Snowflake} channel Parent channel
+   * @param {boolean} [options.lockPermissions] Lock the permissions to what the parent's permissions are
+   * @param {string} [options.reason] Reason for modifying the parent of this channel
+   * @returns {Promise<GuildChannel>}
+   */
+  setParent(channel, { lockPermissions = true, reason } = {}) {
+    return this.edit({
+      parentID: channel.id ? channel.id : channel,
+      lockPermissions,
+    }, reason);
   }
 
   /**
diff --git a/src/util/Constants.js b/src/util/Constants.js
index 447b95875..a88af9f5b 100644
--- a/src/util/Constants.js
+++ b/src/util/Constants.js
@@ -165,13 +165,6 @@ exports.VoiceStatus = {
   DISCONNECTED: 4,
 };
 
-exports.ChannelTypes = {
-  TEXT: 0,
-  DM: 1,
-  VOICE: 2,
-  GROUP: 3,
-};
-
 exports.OPCodes = {
   DISPATCH: 0,
   HEARTBEAT: 1,
@@ -574,6 +567,14 @@ exports.UserFlags = {
   HYPESQUAD: 1 << 2,
 };
 
+exports.ChannelTypes = {
+  TEXT: 0,
+  DM: 1,
+  VOICE: 2,
+  GROUP: 3,
+  CATEGORY: 4,
+};
+
 exports.ClientApplicationAssetTypes = {
   SMALL: 1,
   BIG: 2,