Licence compatibility: why mixing open assets can backfire

Licence compatibility is the hidden snag when you mix openly licensed works. Think of it like a jigsaw where each piece has its own rule: a ShareAlike photo forces your whole project under the same licence, while a NoDerivatives clip forbids any edits. You cannot just stack them—the conditions must align, or the combination becomes legally invalid. For example, pairing a NonCommercial image with a ShareAlike text often fails because the first restricts use to non-commercial contexts, but the second demands the same licence for all derivatives, regardless of purpose.

To spot conflicts quickly, focus on three terms: ShareAlike, NonCommercial, and NoDerivatives. ShareAlike (SA) requires your new work to use the same licence, which clashes with any licence that forbids that (like NoDerivatives, ND). NonCommercial (NC) forbids commercial use, so it cannot mix with a licence that allows it unless you keep the whole result non-commercial. NoDerivatives (ND) bans remixing, so it cannot combine with anything that requires adaptation. A quick elimination trick: if two assets have different restrictions, they likely conflict—stick to the most permissive licence (like CC0 or CC BY) for safe mixing.

Remember this with a simple test: 'SA + ND = no go; NC + anything commercial = conflict; ND + any change = blocked.' If a question presents a mix of open assets, check each pair for these clashes. The key is that 'open' never means 'free for all'—always verify the fine print before combining.