When you connect to play.dungeonrealms.net, you will be logged into a random Dungeon Realms Shard (Server) such as US-1 or US-2. After that, the last shard you logged out from you will log in to the next time you connect. Instead of having to disconnect from the Dungeon Realms servers now to connect to another shard, all you have to do is type /shard. The shard command brings up a prompt like this:
The shard prompt is an inventory that contains green and white colored wool. What you need to know is that the green wool is the shard you’re currently connected to. The white wool are other shards that you can connect to by simply left clicking on the shard of your choosing. By hovering over the shard of your choosing you’ll see the number of players connected to the specific shard.
An important thing to note is that while in a wilderness/chaotic zone there is a cooldown of 5 minutes between switching shards to prevent combat logging and other abuse resulting from such. This was introduced in Patch 1.2-OB.