Quests
Learning paths through this topic
Tell "own ten farms" and "buy ten farms" apart when players sell and receive gifts
One quest asks for a state, the other for actions, and mixing them up lets players sell and rebuy forever, lose a finished goal by selling, or never count a gift. Here is a small rule that keeps both honest, including what finished means once it has happened.
Change a quest's target in an update without erasing or gifting saved progress
After a patch, "defeat twenty" becomes "defeat fifteen", or the other way round. Players with a save in the middle see broken numbers, finished quests that reopen, or rewards that are suddenly claimable twice. Here is how to move old saves to the new numbers fairly.
Decide which quests start over and which stay finished after a prestige reset
After a reset, one player has the same quest twice and a reward they never collected is gone, another sees a bar that runs backwards. Here is a clean split between counters for this round and for all time, and a safe moment to restart repeatable quests.
Fill a limited quest board from a waiting line without wasting time limits
The board holds only a few quests, new ones keep arriving, and either they pile up unseen or their clocks run out before the player ever saw them. Here is a waiting line that starts the clock only when a quest is shown, and fills free places fairly.
Return a quest crate to solid ground when an explosion throws it into a pit
Physics objects carry quests too. A blast sends the crate off the map, into lava or onto a ledge nobody can reach, and the mission can no longer be finished. Here is how to remember where it last stood on reliable ground and put it back there.
Warn about a quest deadline even when the clock jumps ahead
A three-day deadline should warn at the halfway mark and again when little time is left. But sleeping or travelling can leap over both warnings at once, and then you either get two messages in a row or none. Here is the rule for what to say.
Decide what happens to a quest when the person who gave it dies
The player finished the job, walks to the quest giver and finds a grave. Either the quest log shows a task nobody can accept, or the reward is lost. Here is a clear rule set for each situation, so every quest ends in a sensible way.
Keep quest goals and progress bars working past the largest number a game can hold
Late in an idle game, goals grow until the number turns into "infinity", progress shows not a number, and the quest can never be completed. Here is a way to store huge values as a size and a power, add them, compare them, and still draw a sensible bar.
Point a stuck player to the next quest step, a little more each time
Players who put the game down for a week return without a clue what they were doing, while others want to find things themselves. Here is a hint rule that reads the real state of the quest and gets more direct only when time has passed without progress.
Make a rare quest item drop in a fair number of tries at most
At a flat ten percent, some players find the item at once and others grind for a hundred kills and give up. A rising chance after each miss fixes the worst case, but what does it do to the average? Here are the exact numbers to pick from.
Find the way a player can lose the item a quest still needs
The key is given once, the shop buys everything, and ten minutes later the door cannot be opened any more. Here is the search over everything a player can do with their pockets that finds the first moment the quest becomes impossible.
Sort the quest list so that ready rewards come first and rows stop jumping
A player is about to tap a quest and the list reshuffles under the finger because a counter changed. Or the one finished quest sits at the bottom of a long list. Here is an ordering that puts the useful rows first and freezes them while the list is open.