Figured I'd list out all the world magic and what they look like for ease of reference. Ordered left to right on the UI (if only things were WUBRG...)
===Active Use - Risks an amulet every use===
Black - Deck with Cards Being Drawn - Conjurer's Will - 400g Edit deck out in the open
Blue - Jumping Guy - Leap of Fate - 300g Teleport to random location
Green - Winged Sandals - Quickening - 300g Double your land speed
Red - Magic Staff - Thunderstaff - 500g Kill the closest creature
White - Sword - Sword of Resistance - 400g Teleport to a town under siege
====Always On====
Deck Being Shuffled - Slight of Hand - 500g Switch Ante once before duel
Stack of Gold Coins - Haggler's Coin - 500g Increases number of cards sold in Towns/Villages
Dragonfly - Amulet of Swampwalk - 150g Move faster in swamps
Spellbook - Tome of Knowledge - 400g Increases amount of duplicates allowed for each card by one
Carved Apple - Fruit of Sustenance - 300g Gain food in forests
Pickaxe - Dwarven Pick - 150g Move faster in mountains
Ruby Ring - Ring of the Guardian - 600g Wizards need to capture 5 towns/villages to win
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If you stumble on them, Pickaxe and Dragonfly are super useful and cheap (150g)
I've played around with Leap of Fate and Quickening also. They can be useful while playing Hide-N-Seek with the Castles