Spawning a object

[José Valverde]

This is my first time using PuzzleScript and I wanna do a rule to Merge 3 objects into 1 of "Higher Value" and I was thinking to destroy the 3 objects

 late [ Crate | Crate | Crate ] -> [ | | ]

and spawn the object Crate2 but I´m not sure if is posible to do it

[edderiofer]

You can spawn a dummy object instead, and later replace it with Crate2:
    late [ Crate | Crate | Crate ] -> [ | DUMMY2 | ]
and in a later rule,
    late [DUMMY2] -> [Crate2]