Otherside

Otherside lets mobs go through portals like they would in singleplayer, so farms that need this to happen will be possible without needing an alt or friend on the other side of the portal. In vanilla multiplayer Minecraft, mobs don't go through portals if there are people on the target destination and they're all far away from the portal.

About hard despawning

What makes mobs not go through, exactly?

It's a Minecraft mechanic called hard despawning. If a mob is 128 blocks away from all players in a certain dimension, it will despawn instantly. Let's say that Player1 is in the overworld near their portal at x=800 / y=100 / z=800, and a mob goes through to the nether, exiting at x=100 / y=80 / z=100

✔️ If there's no one else in the nether, good! The mob will stay, because mobs don't hard despawn in empty dimensions. This is why these farms work in singleplayer and in servers with only one player.

✔️ Now, imagine there are three players in the server. We have Player1 in the overworld, Player2 in the nether at x=110 / y=75 / z=90 (very close to the portal) and Player3 in the nether at x=5000 / y=50 / z=-2000 (very far from the portal). If a mob enters a portal in the overworld to the nether, it will go through just fine, because the mob is within 128 blocks of a player (Player2). So it won't hard despawn.

❌ Now, imagine Player2 leaves the game and only Player1 and Player3 stay. Mobs will now instantly hard despawn when they get in the nether. That's because Player3 is too away from the portal.

What does otherside do to not let them despawn?

The plugin makes every mob that goes through persistent for 20 seconds (default), so they can't despawn. The time is configurable for each type of mob.

Is this Paper's fault?

No. At least in recent versions (old ones were not tested), Paper works just like vanilla. Mobs not going through portals in some cases is intended.

Commands

/otherside reload: reloads the config. Requires the permission otherside.main