Fork [International Collectors' Edition] Historic Scholars say that arbiters exist

Scholars say that arbiters exist on every world

Set: Judge Gift Cards 2006 Type: Creature — Human Wizard Rarity: Rare Cost: {R} {R}

Set: Arena League 2001 Type: Sorcery Rarity: Rare Cost: {1}{G} Target player shuffles up to three target cards from their graveyard into their library

you may pay {0} rather than pay the mana cost for a spell you cast with mana value X or less

Set: Arena League 2000 Type: Sorcery Rarity: Rare Cost: {1}{R}{R} Destroy target artifact or land

Fork [International Collectors' Edition] Historic Scholars say that arbiters existSet: International Collectors' Edition Type: Instant Rarity: Rare Cost: {R}{R} Copy target instant or sorcery spell, except that the copy is red. You may choose new targets for the copy.