Make it clear that a move can't be made in multiplayer tic tac toe game

Question

I'm building a TicTacToe game as a learning exercise with real-time technologies.

I have the following UI:

Right now, it is Emma's turn to go. How do I make it clear to Dan that he can't make a move?

The ideas I have are:

1. Make the mouse pointer for Dan into something that would make it clear that he can't click on the Board Cell e.g. cursor: not-allowed;
2. Upon clicking, run a micro-interaction on Dan's end (e.g. shake clicked cell a bit and not put the mark in there)
3. Change the colour of the board and its cells to make it clear that they are in a disabled state (maybe grey them out a little)

I'm not really sure which of these would be most user-friendly and which would be best from an accessibility point of view, but also fun and engaging for the end user.

Answer 1

In general, in online games, the message that appears regarding the turns is different for those who have to play compared to those who have to wait:

You can allow Dan to take any action but it will be ineffective until Emma ends her turn (or the wait icon stops rotating).