Factorio Forums

Posted: **Wed May 06, 2026 9:00 pm**

Comparing the 1.1 and 2.0 documentation makes me believe that ItemProductPrototype::type is required in 2.0. However, with the mod Tricky Old Nick, --dump-data (output attached) produces at least one rocket_launch_products entry with no type. For example, at line 65882:

Code: Select all

        {
          "name": "nullius-guide-drone-nickel-1",
          "amount": 1,
          "probability": 0.2
        }

Under what circumstances is type optional in an ItemProductPrototype?

Posted: **Thu May 07, 2026 5:29 am**

In 2.0, `type` is required only in places where there is selection between ItemProduct and FluidProduct. Since rocket_launch_products is always an ItemProduct, there is no need to check what type it is becuase only items are allowed.

As for 2.1, there will be a change that makes code consistent with docs: `type` will be always mandatory regardless of prototype taking only ItemProduct or any product. This means that this data you mentioned will throw an error due to missing type.

Factorio Forums

ItemProductPrototype::type is not always required

ItemProductPrototype::type is not always required

Re: ItemProductPrototype::type is not always required