Its the idea that you spend your cards more efficiently than an opponent, and in doing so, you gain an advantage
The total number of these that will exist can be seen below: 300 Serialized double rainbow foil Sol Ring (Elven) 700 Serialized double rainbow foil Sol Ring (Dwarven) 900 Serialized double rainbow foil Sol Ring (Human) 3,000 Non-foil Sol Ring (Elven) 7,000 Non-foil Sol Ring (Dwarven) 9,000 Non-foil Sol Ring (Human) For those looking to get their hands on a copy of The One Ring, use this handy chart to track down the packs to crack
Attached to an evasive creature like Invisible Stalker, this card ensures your life total never gets close to 0
They also both combo well with your mana dorks, helping accelerate your early game ramp
If a creature spell you cast this turn was countered by a spell or ability an opponent controlled, you may pay 0 rather than pay Summoning Trap's mana cost