# Two people move the same card

Two people watching the same board will eventually drag the same card within the
same few seconds: one triages **Repricing of commercial property after the 2025
flood season** into **In Progress** while the other closes it as **Done**. No
change is ever written on top of a version of the item it did not read, and
anyone whose change cannot be applied is told.

## Before you start

Both people need permission to change the item and to make that particular
transition. AnyKanban writes as the signed-in user, so each person's own
permissions and each project's own work item rules apply, so a move that works for
one of you can legitimately be refused for the other.

## Steps

1. Open the same board in two places, whether two people or two browser profiles.
2. On the first board, drag **Repricing of commercial property after the 2025
   flood season** from **Triage** to **In Progress**.
3. Before the second board has refreshed, drag the same card there to **Done**.
4. Watch both boards through their next refresh, about twenty seconds.
5. Read any message that appears at the bottom center of either board. Messages
   clear themselves after about six seconds, so read it while it is there.

## What you should see

The later drop wins, and both boards agree within one refresh. The second board
keeps the card in **Done**; the first board moves it out of **In Progress** into
**Done** on its own, with no reload and no message.

What happened underneath is the part worth knowing. The second write was
refused, because it was made against a version of the item the server no longer
had. The board re-read the item and applied the same move once more against the
current version, and that retry is all most people ever experience of a
conflict: nothing to notice, and nothing lost.

Two variations behave differently, on purpose:

- **You both made the same move.** Nothing is undone: the retry re-applies the
  state the card already has, together with the position that person dropped it
  at. When the state is the whole change, a checklist box you both ticked,
  the board sees the move as already made and writes nothing at all.
- **The retry cannot be applied either**, because the item changed again or
  because a work item rule refuses the move from where the card now actually is.
  Then the card snaps back to what the server holds, and a message explains:
  *"Someone else changed this item first. The board was refreshed with their
  changes."* for a lost race, or the server's own message when a rule was what
  refused it. A rejected change is never silent.

![A rejected write reverting, with the server's own message](https://anykanban.com/docs/_img/conflict-toast.png)

## Notes

The revision check prevents *stale* writes, not simultaneous ones: it is not a
lock, and two people moving one card is still a conversation to have. The board
only guarantees that both of you end up looking at the same answer. Reordering
is treated differently again: the background rank respacing that sometimes
accompanies a reorder is dropped silently on a conflict, because the next
refresh sorts everyone the same way anyway.

## Related

- [Keep the board open during your daily meeting](https://anykanban.com/docs/work-with-others/keep-the-board-open/)
- [When Azure DevOps rate-limits you](https://anykanban.com/docs/work-with-others/when-the-service-throttles/)
- [User Guide](https://anykanban.com/docs/user-guide/)