Rules glossary
↑ Parent rule: 702.160 Prototype
702.160a Prototype is a static ability that appears on prototype cards that have a secondary set of power, toughness, and mana cost characteristics. A player who casts a spell with prototype can choose to cast that card “prototyped.” If they do, the alternative set of its power, toughness, and mana cost characteristics are used. See 718, “Prototype Cards.”
No sub-rules.