From the back of the box:
Worlds of Wonder contains 3 complete role-playing games, interchangeable in concepts and rules, and supported by a fourth rule set, Basic Role-Playing (1980 Edition), in turn supplying a general introduction and elementary rules for Magic World. Superworld, and Future World. Included are four booklets, a scenario for each world, character record sheets, play-aids, six dice, and introduction to the city of Wonder, character silhouettes, and other enclosures.
This game is complete — there is nothing else to buy.