Ignorant Bliss

A protection spell that guards nothing on the battlefield, only the cards you have not yet committed to it. The mechanism is a temporary exile: your whole hand leaves face down and comes back at the next end step, which means anything keyed to your hand size or hand contents momentarily sees zero. That timing window does all the work. Cast it in response to a forced discard and the discard finds an empty hand; cast it against an effect that counts or reveals your hand and the count comes up empty; and because the cards return on the end step rather than immediately, you collect a clean replacement draw on top of getting the hand back. It is a defensive instant wearing a cantrip's clothes, built for an era when discard-based disruption and hand-size symmetry effects were common enough to justify a dedicated answer. The face-down clause matters too: an opponent who watches you flicker your hand learns nothing about what was in it. Narrow by construction, since it touches no creature, permanent, or board state, but precise: it turns the act of holding a hand into something you can hide and restore on demand, with a card drawn for the inconvenience.