This Polygon guide explains how Mega Evolution works in Pokémon Go, a mechanic that lets trainers temporarily power up their Pokémon for stronger stats and gameplay bonuses. It matters to active players because Mega-Evolved Pokémon boost catch rates, raid performance and candy rewards for their type, making them a key strategic tool, while a related but distinct mechanic called Primal Reversion applies only to Kyogre and Groudon.

To Mega Evolve a Pokémon, players must collect Mega Energy specific to that species, primarily by battling it in Mega Raids, though Field Research, Timed Research and walking with a previously Mega-Evolved buddy also yield energy; only one Mega Pokémon can be active at a time, reverting the previous one to normal. Repeated Mega Evolution raises a Pokémon's Mega Level, increasing its bonuses, and since a recent update players can reach a "Super Max Level" using large amounts of energy (for example 5,000 for Mega Victreebel), unlocking an extra, non-TMable charge move. Not all Mega Pokémon are available year-round, so the guide advises stockpiling energy before a species rotates out of raids, and notes that Super Mega Raids yield more energy and unlock Mega Evolution for caught Pokémon without the usual initial cost.