It depends on which side you are (artist or dev) and in which stage you are (art is done, art must be created).

If the art is already done, the artist should deliver a license included with the art which allows you to use the art. The license describes the way you are allowed to use it (ie use for commercial projects, don't resell as standalone etc.). There are some free licenses available (CC), but it is advisable to contact a lawyer to create your own license, at least if you want to sell it.

If the art is not done yet, and the artist need to create the art according to the requirements of the customer, then you need a contract (btw. a license is a contract too). I don't know if there are contracts freely available for hire-work, but the artist should have an interest in providing one (created by a lawyer), because he want to sell a product or service.

Hi,

Think about the scope of a license compared to a contract. As an artist, I insisted on a contract, so in some cases you may only have a contract available with a particular artist. A contract can add flexibility and simplicity long term. Things can change, too. It is possible to negotiate a plan which changes in the future. Try to not limit your options no matter what if license or contract. Also it is important for legal reasons to be defensive on purpose. Contracts have the potential to offer you more legal protection than licenses, but the legal world has loopholes and exceptions a plenty.

You definately need to research legal issues often - on a permanent basis - and consult a specialist lawyer in copyright and contract issues before enacting a plan.

Clinton