Scripts

Medyan, you described everything rather vaguely. If you need

if there are more than 12, then a dialog is triggered (2); if not, then dialog (3)

, then the code should be

if a>12 then
StartAdvMapDialog(2)
else
StartAdvMapDialog(3)
end

. If the check for the number of creatures should be performed after interacting with the altar, then it should be written in the handler for clicking on the altar.