The server has a custom portals plugin that allows players to create pairs of portals that then allow free travel to the opposite end. To use them, simply stand in one of them and crouch (press shift), and you will be teleported to the opposite portal, wherever that is. Each portal is paired with exactly one other portal, but players are able to create as many portals as they want.
To create a set of portals, first create the obsidian foundation as shown in the picture. This can face either direction. Then in the inside of the portal, place 1 diamond block and 1 lapis lazuli block. If the blocks do not disappear, then the location you are trying to use is already in use by another portal, or the blocks have not been placed properly. Make sure the portal is complete obsidian as shown in the image, including the corners.
Once you've successfully set one end of the portal, you should then travel to where you want the other end to be located. Be careful not to die during this period, if you die before finishing up the 2 portals, the one you've already placed will be lost. When you've reached the other location, simply repeat the process building an identical portal.
The portals allow instant travel, but they can only be placed in the 3 vanilla worlds (the overworld, the nether, and the end.) It is possible to create portal pairs that go from one world to another.
To disable a portal, simply break one of the obsidian blocks. This will permanently destroy both ends of the portal, requiring you to build a new portal at both ends.
All non-player entities within 2 blocks of the portal will be teleported along with you when you teleport.
You can fill the portal in with solid blocks but if you teleport to it from the same dimension you will be stuck in a wall. There is a bug that teleports you to the surface if your filled in portal is in another dimension. This is useful for hiding portals.
Some players choose to use Portal onion routing to increase the security of the portal links.
It is possible to protect your portals from X-ray.
If a pressure plate is placed inside a portal and activated by a player, that player will be teleported as if they had crouched.
The source code for the Portals plugin is available on github.
One way portals
There are two types of one way portals. True one-ways can only be traveled through in one direction, no matter what players do on the end terminal. 1/3-way portals can be traveled through by mining at the end terminal with about a 1/3 probability. This uses the bug mentioned above about solid blocks in portals.
True one way portals
True one way portals use the obsidian block breaking mechanic using withers. Currently (Sep-15-2019), the portal plugin only checks if players break portals to delete the portal from the database, but this doesn't activate if withers break portals. If you use a wither to break a portal, the portal is deactivated, since the portal plugin checks both ends to see if the terminals of the portal are complete (full obsidian). However, this doesn't delete the portal pair from the database. When a player replaces the obsidian block that the wither broke, the portal can be traveled through again.
For slower learners
- Portal pairs only get deleted from the portal database if a user breaks them
- Both portal termini must have complete obsidian circle in order for you to travel through them
- Therefore, if you break a portal with a wither, players cannot travel through the portals, but the portal pair is not deleted from the portal database
- In order to travel through the portal, replace the obsidian that the wither broke
- Make sure the wither breaks the blocks behind you!
1/3 way portals
1/3 way portal use the bug that teleports the player above portals that are filled in IF that player teleports from a different dimension. This usually ends up looking like a large obsidian pillar that the portal is hidden within. Since the plugin only checks if the portal is complete (does not check direction), any players encountering the end terminal of one of these portals has a 1/3 chance of breaking into it. They can also break into it using the wither's block breaking abilities. This would take much longer, but players could discover the correct placement to recreate a full portal every time. By using 3-5 of these in a row, players can effectively make one-way portals that will never be broken into.
Player goes to (100, 65, 100) and builds a portal, it is then activated. Player then travels to (-200, 35, 300) without dying and builds another identical portal there. The two portals are now connected, if Player or anybody else stands in the portal at (100, 65, 100) and then crouches, they will be teleported to (-200, 35, 300). If they stand in (-200, 35, 300) and teleport from that portal, they will be teleported to (100, 65, 100).
If Player had died before building the portal at (-200, 35, 300) then the portal at (100, 65, 100) would have been deactivated, and Player would have had to travel back to (100, 65, 100), put in another diamond block and another lapis block, and then start over traveling to (-200, 35, 300). After both portals are active however, Player can die any amount of times and nothing will happen to the portals.
If someone then breaks an obsidian block at either (100, 65, 100) or (-200, 35, 300) then both portals will be deactivated, even if the obsidian block is put back. In this case someone will have to rebuild both portals.