World and lore
Make sure a one-of-a-kind artifact exists exactly once in the world
A legendary sword is handed out by the quest, found in a chest and sold by a trader, and suddenly two of them exist, or none because its owner fell into a pit. Here is a ledger that always knows who holds it and brings it home when the holder is gone.
Warn the player before a drop they cannot climb back up
A trapdoor, a collapsing bridge or a river ride can leave treasures and people behind for good, and players hate finding that out at the end. Here is how to list every one-way passage together with exactly what it would cost, so you know where a warning belongs.
Count travel days over mixed ground when you cannot stop mid-tile
A road is quick, a forest slow, a mountain very slow, and the party should sleep on a tile, not between two. Dividing the total by the hours in a day gives the wrong number of days. Here is how to plan the walk with real camp spots and a tile that is longer than a day.
Generate place and people names that fit a culture and never look alike
Fifty names in a row and three of them are "Brannor", "Branmor" and "Branner", which readers cannot tell apart. Here is a name generator that keeps each culture's sound, gives the same names for the same world seed, and refuses names that are too close to one already used.
Rename a place after something happens there and still find its old name
After the flood the settlers call the camp by a new name, but old notes, maps and elders still use the old one. Here is how to keep every name a place ever had, say which one is right for a given year, and avoid mixing up two places that end up sharing a name.
Catch names like "Highmoor" that sit in a valley, with a naming glossary
A village called Highmoor in the bottom of a valley makes every reader pause, and nobody notices until a player points it out. Here is a glossary check that splits each name into its meaningful pieces and compares them with how the place really looks, including a trap that eats the wrong piece.
Give places names from the map seed that never change or repeat
Walk to the east first and the village is called Ashford, walk to the west first and the same village is called something else. Here is how to name places from where they are, not from when they were created, and to settle two places that land on the same name in a way that never depends on the order.
Make roaming monster fights neither clump up nor stay away
With a flat chance on every step, a player meets two fights in three steps and then walks eighty steps through an empty field. Here is a gentler rule that gives breathing room after a fight, makes one more likely the longer it stays quiet, and lets dangerous ground count more.
Make a rare wanderer appear by distance walked, never too soon, never too late
A traveller who is meant to be rare turns up three times in an hour for one player and never in twenty hours for another. Here is how to let the chance grow with distance covered, stay at zero at the start, become certain after a set distance, and reset only when the traveller is met.
Simulate who holds which land so that no realm vanishes too early
Your world has four realms and a war in the background, but by the second act only one is left because the strongest simply ate its neighbours. Here is a deterministic round-by-round walk over the map that shows who survives, who falls and when.
Decide which region applies when two areas overlap on the map
A farm sits inside a forest that lies inside a kingdom, and each of them wants to set the music, the weather and the danger. Here is a clear rule for which one wins at any spot, how borders are cut, and how to catch two areas that tie.
Respawn herbs and ore correctly for the time the player was away
Come back after a week and every bush should be full, but come back at the very moment you picked the last berry and the next one should not appear at once. Here is how to catch up the time you missed without banking free refills.