29 cards where the text includes “3 damage to each creature”

Anger of the Gods (Double Masters 2022 #102)
Blasphemous Act (The Lost Caverns of Ixalan Commander #216)
Brotherhood's End (The Brothers' War #128)
Caldera Hellion (Shards of Alara #95)
Claws of Wirewood (Vintage Masters #201)
Conductive Current (Alchemy: Innistrad #38)
Dakmor Plague (Masters Edition IV #73)
Deafening Clarion (Guilds of Ravnica #165)
Falling Star (Legends #145)
Famine (Vintage Masters #120)
Fast // Furious (Modern Horizons 2 #123)
Festering Evil (Weatherlight #68)
Firespout (Ravnica: Clue Edition #190)
Flamebreak (Darksteel #61)
Gruul Charm (Gatecrash #169)
Hostile Takeover (Streets of New Capenna #191)
Incendiary Sabotage (Kaladesh #119)
Infected Vermin (Odyssey #144)
Invasion of Karsus // Refraction Elemental (March of the Machine #146)
Invasion of Karsus // Refraction Elemental (March of the Machine #146)
Krazy Kow (Unglued #48)
Magma Phoenix (Magic 2011 #150)
Slagstorm (Mirrodin Besieged #75)
Spontaneous Combustion (Conspiracy #194)
Strategy, Schmategy (Unsanctioned #58)
Sulfurous Blast (Commander Masters #262)
Sweltering Suns (Amonkhet #149)
The First Eruption (Dominaria #122)
Thunder Dragon (Commander Legends: Battle for Baldur's Gate #810)
Thunderwave (Commander Legends: Battle for Baldur's Gate #201)

Their mind whirled with grand plans, never thinking of what might happen if they got to the end of the list.