Module variable assignments are inherited from the parent module and do not need to be explicitly set.

This is false because Terraform enforces explicit variable assignment in module calls; variables from the parent namespace are never automatically propagated to child modules.

In Terraform, each module operates in its own isolated namespace, and the parent module must explicitly pass values to child module variables within the module call block. There is no implicit variable inheritance across module boundaries - Terraform will return an error for any required variable not assigned in the module call unless it has a default value defined. This explicit passing is required regardless of whether the parent module has a variable of the same name.