Saving
Learning paths through this topic
Playing on phone and computer gives two different saves and one overwrites the other
When the same player continues on a second device, someone has to decide whose progress survives. Taking the newer file loses work, and adding numbers together invents money. Here is a merge that keeps what both sides did.
Two players save at the same moment and one of them loses their gold
When two people change the same shared record, the last write quietly erases the first. Here is how to combine both changes the way people expect, which things add up and which cannot, and how to report a clash instead of hiding it.
The host leaves and the friend who takes over has an older version of the world
When a game moves from one host to another without a server, picking just anyone can send everybody back in time. Here is how to choose the person who knows the most and how the others catch up, and what honestly gets lost.
After loading, new objects get the same number as saved ones and mix up
Every pet, arrow and cart in an online game needs a number that messages can point at. When a save is loaded, the counters that hand out those numbers can start in the wrong place, and two different things answer to the same name.
A phone game uploads months of offline progress and breaks the shared profile
Not every part of a profile can be treated alike when an old device finally reports in. Some things only ever grow, some are collections and some must be refused unless the device saw the latest state. Here is a sorting of fields that decides this.
One player's damaged file stops the whole world from starting
With many people in one world, sooner or later one file is broken, and a loader that gives up at the first error locks everybody out. Here is how to load the rest, fall back to an older copy for the broken one, and keep the evidence.
Two servers load the same world and each one overwrites the other's progress
After a restart, a slow or hung server can wake up and keep saving as if nothing had happened while a new one already runs the world. Here is how a world can only be held by one server at a time, and how the old one is stopped even when it does not know.
The party leader goes offline and the group falls apart or fights over the lead
A saved group needs to know who is in it even when most are away, and who leads when the leader's connection fails for a minute or for a week. Here is a rule that is calm about short drops, hands over once, and does not swing back and forth.
After a party wipe, some players restart far behind and others far ahead
Checkpoints in a game for several people have a problem a solo game does not: who has to stand there for it to count? Here is a rule that does not let one fast player drag the group's restart point away, and how it is saved.
The owner logs out and their pet vanishes or their cart strands a passenger
Things that belong to one player but exist in a shared world need a rule for the moment that player leaves, and the rule differs for a pet, a parked cart and a cart with a friend still aboard. Here is a set that stays consistent through saving.
A dropped connection throws the player back to the menu and costs them their place
Phones switch networks and laptops sleep, so short drops are normal, not a reason to start over. Here is how a player can slip back into the same seat shortly afterwards, without letting someone else take it or reuse an old key.
A returning player's saved spot is now inside a wall someone else built
A shared world keeps changing while a player is away. Their old position can become solid, flooded or taken by another player who just logged in. Here is how to pick a nearby place that is truly free, the same way every time.