Older child chooses one skill they have that the younger sibling genuinely can't yet: tying a knot, folding a paper airplane, drawing a specific animal, sorting playing cards by suit. They teach it. The framing is critical: not 'help your sibling' (babysitting) but 'teach them what you know' (expertise). Most older children who complain about their younger sibling will enthusiastically teach them something if the authority structure is made explicit.

What you need

Whatever the chosen skill requires (paper, rope, cards, pencil)

How to do it

1Ask the older child: what's one thing you can do that they genuinely can't yet?
2Say: you're the expert here. Teach them. Not help them. Teach them.
3Hand over whatever they need and step fully out of the room.
4Don't observe the teaching. The lesson is theirs, not yours.

Variations

If the older one refuses to teach: ask what they'd want to be asked to teach, rather than assigning a skill — ownership of the choice usually unlocks the willingness.
How it ends: have the younger one demonstrate the new skill once, badly or well, while the older one watches as the proud expert.
This one builds cooperation before it's needed. For an active fight, use The Separate Reset (B006-20) instead.

💡 Parent tip

Do not correct the teaching method. An older child who ties a knot the 'wrong' way but successfully transfers the skill has done something real. Correcting the pedagogy destroys the authority structure you just established.

What your child develops

Metacognitive skill — teaching something requires understanding it well enough to explain it, deepening the older child's own mastery
Status through competence — the older child's frustration with the younger is often an identity threat; expertise restores it
Genuine inclusion — younger child learns something real, which is more satisfying than being 'played with'