Two ways a resource qualifies
A resource qualifies if it has a suitable licence or the rights holder's permission. There is no third way
An external resource is everything the level brings with it: music, images, fonts, texts, any files. Each resource has to satisfy one of two options
Option A: an open licence
The resource already carries terms as free as CC BY-NC or freer.
It keeps its own terms. It is not converted into CC BY-NC
What the standard profile accepts:
- CC0 - public domain
- CC BY, versions 4.0 and 3.0
- CC BY-NC, versions 4.0 and 3.0
- MIT and Apache 2.0 - for text and code
- SIL OFL 1.1 - for fonts, it has to be named in the metadata
- Unlicense
Take CC0 whenever the choice is yours. It is the only licence that asks nothing of the level
What the profile refuses
- Proprietary, "all rights reserved"
- CC BY-SA - the level would have to become CC BY-NC-SA, which is not what levels are distributed under
- CC BY-ND - it forbids modification, which the game does not support
- CC BY-NC-SA and CC BY-NC-ND - for the same two reasons
The GPL family is not on the list, even though it is freer than CC BY-NC. GPL code cannot be redistributed through the App Store without colliding with Apple's terms. So anything reaching an iOS build has to stay MIT or Apache shaped
The profile depends on the service
Which licences are accepted is decided by the service, not by the licence. The list above is the standard profile. A store build accepts less, and a community server can accept something else
Option B: the rights holder's permission
A private "sure, go ahead" is not enough.
A level under CC BY-NC is redistributed publicly, and the permission has to cover exactly that, not your personal use
A valid permission grants all three of:
- The right to use the resource inside a Bullet Hero level
- The right for that level, the resource included, to be freely and non-commercially redistributed by third parties through the game's services, with attribution
- Explicitly non-commercial use only
How to ask - Asking an author for permission
A permission does not turn a refusal into a pass. If the resource's licence is one of the refused ones, the permission sends it to a human review, but never makes it "allowed"
Scope and validity
A permission with no stated scope or no evidence counts as incomplete. An expired permission counts as nothing at all
The scope is recorded, and it matters:
- a permission for one named level is void the moment the resource is copied into another level
- a permission for any level survives every reuse