Short Answer 
In Minecraft, Nether portals link based on their horizontal proximity, requiring them to be within 128 blocks in the Nether to connect to the Overworld. For separate portals, players should ensure they are at least 128 blocks apart. This linking mechanism specifically applies to the Java Edition, with other versions possibly having different rules.
Understanding Nether Portal Linking
In Minecraft, Nether portals create a connection between the Nether and the Overworld. The linking mechanism depends on the distance between portals in the Nether. Specifically, portals can link to each other based on their horizontal proximity within a defined range.
Distance Requirements for Linking
For portals to link properly in Java Edition, they must be within a range of 128 blocks horizontally in the Nether. Here is how it works:
- 1 block in the Nether equals 8 blocks in the Overworld.
- If two portals are within 128 blocks of each other in the Nether, they will create a link to a corresponding portal in the Overworld.
- If you want separate portals, ensure they are at least 128 blocks apart in the Nether.
Version Specific Mechanics
It’s vital to remember that this linking behavior is specifically for Java Edition of Minecraft. Different versions or platforms may have slight variations in how portals function. Therefore, it’s advisable to check the specifications of the version you are playing to understand the unique mechanics of Nether portals.