Continuing in the series I'm calling The Thirty-Six, based on Georges Polti's The Thirty-Six Dramatic Situations (original version and a modernized ta...
Sometimes the DM has to send a rescuer to avert a TPK. This can seem like the hand of God tweaking the PC's nose. So, best if the rescuer fits into the narrative, somehow, and it's also best if the rescuer helps the party survive rather than single handedly waltz in and save the day.