How do you make a portal in Minecraft?
user
To build a portal you need a flint and at least 10 blocks of obsidian. Arrange them into a vertical rectangle (3 vertical, 2 horizontal) without (or with if you have more obsidian) vertices. Now all you need to do is set fire to the inside using flint.
assistant
Can you represent the portal visually for me in text?
user
OO
   O    O
   O    O
   O    O
     OO

Where "O" represents an obsidian block. To make the portal functional, you'll need to ignite the center of the portal using a flint and steel. The fire will then ignite the obsidian, creating a usable portal that can be used to travel between dimensions.
assistant