Hola
pidiendo autorización expresa a sus respectivos autores, o bien utilizando juegos en la que sí se permita su libre uso y/o distribución....
Mira, por ejemplo:
en esta web te dejan añadir sus juegos en tu Web.
http://www.free-web-games.com/ Como éstas debe haber muhcas más.
Entonces debes mirar en laWeb las condiciones o licencia de uso:
Cita: Limited License of Use
We hereby grant you a non-exclusive, revocable right to use any of the online Shockwave Games above (Not Flash Games) on Free Web Games's site
www.free-web-games.com for your own website only.. However, you may not modify, decode, re-compile, or repackage these games as a download or with any adware or other programs. We reserve all of our rights to images, trade names, trademarks, copyright and all other intellectual rights. We reserve the right to revoke your license at any time by giving you written notice, as well as, the right to modify this Agreement, at any time, by posting a change notice or a new agreement on our site.
We will not be liable for direct, indirect or consequential damages; or for any loss of revenue, profits or data arising in connection with using these games or your site, even if we have been advised of the possibility of such damages. These web games are provided as is and are intended for entertainment purposes only.
Saludos