SANJIESAN LORE / Seasonal geography
Keep the seasonal crossing state with the fictional map
A fictional crossing can be open in one season and unavailable in another, if the setting establishes that change. The difficulty appears when a later scene uses the earlier state without explanation. Keep two explicit states for the crossing and check the few scenes that rely on them, rather than building an entire climate simulation.
Use the draft’s condition, not guessed science
Write the condition the story actually states and name the two states it produces. Leave physical details unresolved if the author has not decided them. World Anvil’s timeline reference includes recurring calendar events, which can help place a fictional seasonal change; the tool does not verify the geography or weather. Avoid claiming that a real river must behave the same way, or adding a dangerous real crossing instruction to explain the invented route.
Attach each scene to the intended state
Put the departure, attempted crossing and next arrival beside the stated story period. Inspect any dialogue that assumes the crossing is always available. A character can be mistaken, but mark that mistake as intentional and show the relevant consequence in the draft. Keep the map symbol or note consistent with the state shown by that edition. If the date is undecided, leave the route decision open instead of choosing whichever season makes the scene easier.
Keep the small dependency visible
Save the two states with the scenes and map references that depend on them. If moving a festival or departure date changes the state, flag the affected passage rather than silently redrawing the whole region. A narrow seasonal rule is enough when it supports the story’s actual choices. In an established setting, use approved geography and periods; this original exercise must not create a new official seasonal restriction or travel fact.