Playing on two devices, the last save wipes out what I earned on the other

A player finishes levels on the phone, then plays a bit on the tablet, and the tablet's older save replaces everything. Choosing one save and throwing away the other is the easy answer and the wrong one. This entry merges two saves field by field, including coins.

Why this works

Each kind of data has its own honest way to combine: things earned only grow, records keep the best, and spendable money needs the change each side made since they last agreed.

When not to use it

Skip merging when a server holds the only true save and devices just show it. There, always load from the server and refuse stale writes.

In the full entry

• What to build, step by step
• Starting values and the reason for each
• 3 common mistakes and the fix
• A diagram of every state
• 25 lines of example code with 4 checks that pass
• How your AI shows you that it works

Say this to your AI

Use the Spielerando entry "Playing on two devices, the last save wipes out what I earned on the other" (read_entry two-phones-overwrite-each-others-save) in my game. Build it step by step, and show me how you checked that it works.

Or skip this and connect the MCP: your AI then finds all of this by itself.Connect the MCP