You flip it at the start of your first turn, you put it in your center Spell & Trap Zone, and from that point it boosts your Ancient Gears by 300 ATK
If you really think about it, there have been cards of every type that have been too good, overpowered, and unhealthy like Skullclamp for equipment, Jace, the Mind Sculptor for planeswalkers, Yawgmoth's Will for sorceries, and so forth, but Wizards wisely realized that you don't just give up on equipment altogether because they messed up with Skullclamp or planeswalkers because they had to ban Jace, the Mind Sculptor in Standard
Pay the cost, discard Shark Typhoon, and you can create a flying shark token with attack and defence equal to that extra mana you paid.
Mystic Compass Rarity: Uncommon TYPE: Artifact SUBTYPE: - CMC: 2 Mana cost: USD: $0.36 EUR: 0.20 TIX: 0.00 EDHREC RANK: 23859 , : Target land becomes the basic land type of your choice until end of turn
cards are smaller in their dimensions