Whether your work is set in the here and now, the historical past or a fantasy or futuristic universe, you need to set its boundaries and parameters. To do so well does not always mean to do so with great explicitness.

In the story "Bloodchild" by Octavia Butler, she barely describes the landscape of the alien world. There is a Preserve where Terrans live. There are livestock and native fauna. There are "call boxes," somewhat few and far between, implying a low level of technology, although it's also established that Terrans first came to the world through some form of interstellar travel. There are vehicles, but only the Terrans (not the T'Lic on whose world the story unfolds) have guns. We can relate to some of the details, the rest we must fill in from our imaginations. I find myself drawing on my mental image of remote stations in the Australian Outback when conjuring the landscape and settlements of "Bloodchild." The world of this story arises out of the interface of Butler's sparse details — the velvet of the alien matriarch's body surface, the eating of sterile eggs — and what we, Butler's readers, bring to the table.

In Marilynne Robinson's novel Housekeeping, the initial world building is centered, ironically, around anything but the house the sisters Ruth and Lucille grow up in. We learn instead about their extended family, largely in terms of various characters' flight or escape from the family home, the town of Fingerbone, and the mortal coil. The very family name, Foster, suggests a lesser form of parenting -- and the town, with its scary, skeletal name and thirsty lake, is not a place that feels welcoming or secure. By the time Robinson begins to describes the five, brief serene years in the Foster house, when the girls' grandmother's "bread was tender and her jelly was tart, and on rainy days she made cookies and applesauce," we understand that the currents are deeper and crueler than can be tamed by domestic niceties. This is masterful if oblique world building -- creation of momentous voids and absences as much as the actual spaces that the characters inhabit.

Prompt: People often value lavish descriptions. Try going for the opposite. Think about your narrative world and constrict the details you provide to describe it. Take an existing descriptive passage and slash it. Decimate it. Perhaps it's about trimming adjectives or inessential visuals. Or look away from the physical built word and see if you can evoke a culture, a community (or lack of it). You can always go back and add details back in again, but for now, see if less could be more.

Or Anti-Prompt: If you started out as a minimalist or are working in a spare form, poetry or flash fiction, perhaps you could benefit more from turning this prompt inside out and piling on some setting. Even so, don't be indiscriminate. Choose carefully, be highly specific, including only details that are essential to your story. Ask yourself if they add value — and be sure to leave room for your reader to fill in parts of the world.

Whether you're adding or subtracting, the idea of this prompt is to build yours readers' agency by maximize spaces in which they can project their own material into your world.