Overloaded defender
A piece asked to guard two things at once guards neither reliably. Find the second job, then take the first.
White to play
Rxe6
Both the knight on e6 and the bishop on c7 lean on the queen. She can answer one capture, not both.
What to look for
One enemy piece is the only thing defending two of your targets. Count defenders on each target and see if the same piece appears twice.
When it applies
Whenever you have two captures available and each is answered by the same recapture. It costs nothing to check — take one, and if the recapture abandons the other, you are a piece up.
How it goes wrong
Overload is not the same as a piece being busy. If the defender can recapture and still hold, or a second defender exists, there is no tactic and you have just given material away.
Where it came up
Not cited in your current game.
Practise it
No positions yet. When you miss this idea in a game, the position it cost you shows up here — and in the practise set — with the answer hidden.