Effect

Packet ID	Direction
0x3D	Clientbound

This is sent by the server when it expects a client to play a sound effect or spawn a particle.

Clientbound

Field	Type	Description
Effect ID	Integer	The ID of the effect to play. See Effects
X	Integer	The X position of where the effect is played.
Y	Byte	The Y position of where the effect is played.
Z	Integer	The Z position of where the effect is played.
Data	Integer	Additional data for the effect.

Example Packet

Field	Value
Effect ID	1005 (MUSIC_DISC)
X	105
Y	72
Z	649
Data	2257 (cat)