Creating night sky maps does not require math more complicated than the beloved “roll dice and add or subtract modifiers.”
Fantastic tools exist to generate night skies on demand.
Stellarium1) can help generate the night sky view from Earth from historical time to the future.
Generate night skies for planets around other stars within Celestia2) 3):
Fantasy settings can still use this technique by secretly picking a nearby G-class (or other appropriate) star as a stand-in.
How do the constellations change with the seasons?
The night sky changes throughout the year, with different constellations rising and setting each night at varying times.
A few moments thought can prepare seasonal lists of the key constellations Adventurers may encounter at those times.
Equinox and solstice celebrations in the setting make great milestone points for designing a “procession of the heavens” changing constellation table.
Review the changes in the night sky for each equinox and solstice to update the mental picture of how constellations shift over time.
How many constellations can the Adventurers name?
Historically, the night sky held great importance to people around the world.
Many cultures wrote their stories into the sky, leading to the modern constellations which exist today.
A fantasy setting presents a great opportunity for Adventurers to name their own constellations within the setting, or learn much more about the cultures of places visited while adventuring by simply looking up and asking questions.
A modern or futuristic setting can also tie deep lore, rumors and clues into the existing constellations.
Adventurers can also use the night sky in Skill checks such as: