Java Edition:Occupied Bed
Beds are supposed to only be occupied when a player is sleeping on them. However, with some trickery, the bed can be fooled into thinking that there is someone sleeping, permanently (or until you break the bed).
Trying to sleep on the bed gives the message "This bed is occupied" despite looking unoccupied. Looking at the bed with F3 confirms the state occupied:true.
Obtaining
Sleep Limbo Abuse
With a sufficiently high ping, you can confuse the game into a state where the client thinks player is awake, while the server thinks player is sleeping.
If you then unload the chunk with the bed (by walking far enough away, for example), the game will wake you up (as you don't have a bed anymore), but, because the bed is unloaded, it remains occupied.
[test] starting and ending ranges, and if this (at least at this point) is a bukkit only bug.
Zombie Waking Up Villager
From 19w11a to 19w14b a bed will keep its occupied state set to true if a villager sleeping in it gets woken by a zombie.[1]
Sleeping Villager
If lightning strikes near a villager sleeping on a bed, the villager will be converted to a witch and the bed will remain occupied.[2] Villagers can sleep in beds from 19w11a onwards, and this bug was seemingly accidentally fixed in 24w36a, making 24w35a the final version this is obtainable in.