While it is possible to play a single game, unrelated to any other game events past or future, it is the campaign for which these rules are designed. It is relatively simple to set up a fantasy campaign, and better still, it will cost almost nothing. In fact you will not even need miniature figures, although their occasional employment is recommended for real spectacle when battles are fought. A quick glance at the Equipment section of this booklet will reveal just how little is required. The most extensive requirement is time. The campaign referee will have to have sufficient time to meet the demands of his players, he will have to devote a number of hours to laying out the maps of his "dungeons" and upper terrain before the affair begins.

Preface of the Original Dungeons & Dragons, (1 November 1973)