Double blind

For my boardgame I need the players are invisible each other unless they are in the same cell of the grid. Perfect could be if the Master can decide who is visible to who time by time. Is it possible? and if yes how? Thanks

The only way to handle that would be to create multiple maps and split the party to different maps based on which room they are in.  On a Plus or Pro subscription, you could use Dynamic Lighting to let them only see their current room. 

The first is possible, but is not so practical. I'll upgrade for a month my account and test the Dynamic Lighting. Thanks 

I experimented a bit and got something sort of working. If you have a token emit a very small radius of light (<1), it will only be able to see its own space. With semi-transparent tokens, the player would be able to see through their token and see that another token is there. Setting the tokens AFoW Reveal Distance to something that covers the entire page would let them see the board in grayscale, and they would only be able to see other tokens in their space.

Well I set something that could be working ...  I set the AFoW with all the token visible for the GM only and the Dynamic Lighting on, than the tokens have an advanced setting with light on a limited radius, other players cannot see the light, and the token has a view of 360 degree same radius of the emitted light. The result is that the players can see only in the range of the light radius and the other cannot see the token unless in the range. Ths can be working for me but there is an drawback problem. The token can see the map only in dark grey unless for the light range. This is a minimal problem, indeed. I would now test the possibility to flip the token back in order to hide the tipe of token even if in the light range of the others.