Bookmark it. When the kids say "I'm bored," open on a phone and let them pick a number.
Build a pillow fort
Make an obstacle course through the living room
Indoor treasure hunt (hide 10 pennies)
Paper airplane contest
Bake cookies from a mix — they do everything you can let them
Draw self-portraits without looking down
Dance party with a weird genre (salsa, polka, K-pop)
Indoor picnic on a blanket
Read a book out loud, take turns by page
Play 20 Questions
Homemade play-dough (flour, salt, water, food coloring)
Sock basketball into a laundry bin
Sort all the Legos by color
Freeze tag with only whispers allowed
Simon Says (one kid leads)
Make a "restaurant" — menu, orders, pretend money
Puppet show with kitchen utensils
Write a letter to someone — actually mail it
Time how long can you balance on one foot
Listen to a kids' podcast episode
Make paper snowflakes (any season)
Mirror game — copy each other's movements
Charades, no rules
Fort building engineering challenge (prize: snacks)
Sculpt something from aluminum foil
Interview each other on video
Yoga for kids — find a 10-min video
Design a board game on paper
Play old-school hangman
Nap. Seriously. Try it.
Rotate through. Don't pick their favorite first — save it for the true meltdown moment.