As vs At

When should I use as or at in execute?

`execute as`

execute as changes the executor of the command, or the “who”. After using it, @s will reference what was set. If you execute as multiple entities, the command will be run for each entity, with @s referring to the current entity being run as.

Example:

Make every sheep become NoAI:1b

execute as @e[type=sheep] run data modify entity @s NoAI set value 1b

`execute at`

execute at changes the location of the command, or the “where”. After using it, ~ ~ ~ will reference the position of the set entity. If you execute at multiple entities, the command will be run for each entity, at each’s respective position.

Example:

Set the block under every sheep to be a diamond block
execute at @e[type=sheep] run setblock ~ ~-1 ~ diamond_block

Or, you could use both.

execute as @selector at @s is very common. Don’t try to do execute as @selector at @selector because this runs the command for every entity specified; then runs the command at every entity specified. Remember,

execute as @e at @e

is equivalent to

execute as @e run execute at @e

(see why you shouldn’t do this though)

which would mean:

For every entity, run the following as @s
For every entity, run the following with ~ ~ ~

And thus commands are run way too many times; and not at the targeted entity’s position. Use at @s.