While often worldbuilding is all about precisely defining a fictional world, sometimes it may be better to leave things a bit vague. This approach can be useful in a variety of ways. For instance, in tabletop games players may not behave as anticipated – a game master worldbuilder may wish to keep certain elements vague until fully encountered by the players. The big bad may have been originally designed as an orc but switching them to an elf may provide interesting narrative opportunities that only became apparent as the game developed. Or that forest temple that the players refused to enter may be repurposed as a desert temple encountered later, a change only possible due to a bit of flexibility.

Keeping things vague can also be useful in worlds that develop over installments or worlds that may be subject to change overtime. Worldbuilders often change their minds, and their worlds, when they are struck by new ideas. Leaving certain aspects of a world intentionally vague can leave room for it to grow.