The cantrip minor illusion is particularly versitile. These ideas are to spur thinking – of the characters in the party who have the cantrip, as well as everyone else, who might suggest a good idea in a pinch.
Of course, you should read the spell.
https://www.dndbeyond.com/spells/minor-illusion
Some highlights: an object/sight, OR a sound, but not both (though two casters working together could create both sight and sound). The image can look like someone in particular or sound like someone in particular (unlike Prestidigitation or Thaumaturgy).
Here are some ideas:
Sounds
- Horns of alarm
- Sounds of battle
- An angry lord, shouting
- Coitus happening
- Music playing, drums beating
- A creature roaring
- Pitiful pleading
- Snide laughter or Boing! (like a soundtrack)
- Window breaking
- Approaching guards
- Merrymakers
- Ritual chanters
- Mosquito buzzing
- Footsteps upstairs
- Door creaking or slamming
- “distant” howling
- Distant explosion or thunder
- Fake summons
- Soundtrack sounds
- opens a chest or door, womp womp sad sound, laughing
- breaking glass or dishes, bells ringing, chime, gong
- vomiting, farting, coitus, chanting, hawk screach, wolf howl
- thunder/rain, nose honk
- White noise to mask conversation
water falling, leaves rustling, insects swarming
Objects
- A very still, inquisitive, judgmental cat (or other familiar animal)
- A dangerous looking but barely-chained dog, sleeping for now
- broken bottles
- very still and very. large bug, rat, or scorpion
- Dungheap
- Wrecked doll (that resembles someone)
- Painting that resembles someone (jacked up painting that resembles someone)
- Huge, open bear trap
- Statuette or figurine. Generic, or of someone in particular
- child, enemy, prisoner, warrior dwarf, constable, cleric, dog/wolf, giant bug
- Stolen item is still there
- “Got your nose,” coin out of ear
- Body hung in a tree or crucified
- Something convenient to hide behind
- Valuable item
- art, treasure chest, wand, weapon, potion, pile of coins, sacred pouch, important envelope
- Badge of authority
- False information
- on papers, wrong book, different badge/emblem
- Hide something in a bigger something
Sights
- Large bloodstain on someone’s shirt, or bleeding
- Pee stain on someone’s trousers. Or worse.
- Bad underarms stains on someone who would not appreciate it
- Broken, bloody body
- Large wasp nest
- Baby-sized bundle wrapped in a blanket
- Pile of loose coins
- Make an object ridiculous – flowers, painted strangely, made of ice, a very wrong color
- Dangerous opening
- pit, doorway, acid pool with bones, quicksand with object
- Disguised terrain
- Hidden doorway, window, portal, caltrops,
- Distracting visual
- naked image, befouled image, graffiti, badly burned something, bloody jacked helmet
- Already-spilled or poured acid or wine, or blood
- Pool of blood, barf, pee, milk
- Entertaining sign, well placed
- free everything, free meade, humans only, Thayans Welcome, Buggery here, assclown, closed by order of the duke, Plague!
- Trip up
- Table’s surface as 1 inch higher than truth, door misplaced, steps off
- Doorknob slightly off