Mob tickrate is too slow, and only the server controls entity velocity.

When the multiplayer server was first developed in 2010 during the Alpha stage, the mob tick rate was set to 2, and then in an unknown version, it was changed to 3.

But in singleplayer, before the internal server was created, The living entity tickrate was always 1, making them look smooth.

Ever since the 1.3.1 update, which was released in 2012, mobs have been running at a slower "tick" rate, making them move noticeably slower than in previous versions like 1.2.5.

The issue stems from the server's living entity ticks running at 3 ticks rather than 1 tick, which affects the movement of various entities, including players, falling blocks, TNT, experience orbs, and dropped items. This explains why the movement is sluggish for some players who played earlier versions, or they have dealt with OCD symptoms.

While this can be corrected by changing the tick rate back to 1, In versions before 1.7, where Netty wasn’t used for packets, it can make the client severely out of sync.

I have created a Fabric & FML1 mod that fixes this bug, which is called “No Mob Latency”.

It is available on Modrinth and CurseForge.

Video explanation: https://youtu.be/ciswW7Vcgk0?si=GSEspWPZpk3mzbXS

Before fixing this bug, you will have to add an additional fix which makes the entity not lerp through the ground. You will also have to optimize the server to not be affected by this change.

Steps to reproduce this bug:
1. Spawn any mob.
2. Hit the entity. The mob movement is slow and interpolated too much.
3. Launch an instance of Minecraft in version release 1.2.5, create a test world and spawn a mob in creative mode.
4. Hit the entity. The mob movement will be very smooth.
5. Launch another instance of Minecraft in version release 1.3.2, load the same test world and spawn a mob in creative mode.
6. Hit the entity.
7. The mob movement will be interpolated by 3 ticks, but it also looks teleporty due to the client and the server both fighting to control the mob velocity.
8. Launch yet another instance of Minecraft in version release 1.8.9, load the same test world again, and spawn a mob in creative mode.
9. Hit the entity.
10. The mob movement should now be controlled entirely by the server, which makes it look worse than in earlier versions before the 1.3 update from 2012.

I’ve been modding Minecraft Java Edition for a while now, and this bug has been triggering my OCD since I noticed it.

LivingEntity movement should be controlled by both client and the server, but only if the velocity is not zero.