-Ok, now don't forget the terrain tag we used, it will be very important in a minute.
In this step we will set up the common event used to decide whether the player is on the tile or not, and then call forth the monsters to attack!
So, open up the database, and go to common events. Make it parralel, and choose whatever switch you want (it is important to remember the switch #)
Then, use a control variable command, and set up the variable to whatever number you feel like, the operation to "SET", and the operand to "CHARACTER". Next to character there are two drop down lists, one is for what character (the left drop down list), and the other is for What about them should be the variable value. The first should be "PLAYER" which we should leave alone, the second list should be changed to "TERRAIN TAG"
Screen shot
what we just did was make a variable be the same value as the tile's terrain tag that the player is standing on. So if the player is standing on the tile we set as 3 or whatever value, then the variable will be equal to 3 or whatever value.
Now, in the same event, we need to make a conditional branch, change it to variable, change the variable to whatever variable we used in the conditional branch, and make it a constant of the value we set the terrain tag to (I.E: 3).
screen shot
Next, inside the branch, we need to add "CHANGE ENCOUNTER" and make it "ENABLE". Then, after "ELSE" inside the branch, add another "CHANGE ENCOUNTER", but make it "DISABLE".
What this does is think "Is the variable equal to (number)? If YES, then the player can encounter monsters, if NO, then the player cannot."
Screenshot of the final event:
Now, we aren't done just yet, we need to make some final adjustments to our world in step three.