Messages

You can also use  Game.DoOnceOnly(unique_string)  for this:

Code: ags

  if (HasPlayerBeenInRoom(3) && player.PreviousRoom == 4) {
    if (Game.DoOnceOnly("was in 3, entered from 4")) Display("The message to show.");
  }

Wow! It works and is more elegant! Thank you very much. There are a lot of "prefabricated" commands that I still do not know

Ok, I tried this and it works!

Room1:

Code: ags

bool messagestage1 = true;

function room_AfterFadeIn()
{

if (HasPlayerBeenInRoom(3) && player.PreviousRoom == 4 && messagestage1 == true) 
{
  Display ("The message to show.");
  messagestage1 = false;
}
}

Because I need the message to not be displayed every time the player crosses from 4 to 1.

Thank you to everyone, your answers guided me good!

[only once]

I tried several ways to get this, but they didn't work:

I have the following rooms, starting at room 1:

3
|
2
|
1 - 4

I need a text to be displayed (Display format and only once) when you goes from the room 4 to the room 1 but only if you have visited room 3.

I know that it sholud be easy, but a don't get it. I deleted all the code related, so I can't not show what I'm trying, sorry 

Any clue?