Mischief of the Gnomes

Normal Trap Card

This turn, reduce the Levels of all monsters in each player's hand by 1 (even after they are Summoned/Set). You can banish this card from the Graveyard; this turn, reduce the Levels of all monsters in each player's hand by 1 (even after they are Summoned/Set).

Rulings – Yugipedia

Printings:

Secrets of Eternity: SECE-EN081 (Common) - 2015-01-15
Machine Reactor Structure Deck: SR03-EN034 (Common) - 2017-04-13
OTS Tournament Pack 21: OP21-EN023 (Common) - 2023-02-09

Prices:

Cardmarket: 0.86 €
TCGplayer: $ 1.15