In each generation, there is typically at least one group of Legendary Pokémon that form a trio. Each Trio is seemingly subject to another Legendary Pokémon.
- Regice, Regirock and Registeel – The Legendary Golems, ruled by Regigigas.
- Groudon, Kyogre and Rayquaza – The Weather Trio, led and ruled by Rayquaza.
- Uxie, Azelf and Mesprit – The Lake Trio, ruled by Arceus.
- Dialga, Palkia and Giratina – The Creation Dragons, led by Giratina, and ruled by Arceus.
- Reshiram, Zekrom and Kyurem - The Tao Dragons, led and ruled by Kyurem itself.
- Cobalion, Terrakion, and Virizion - Three Pokémon based on the titular characters of the novel The Three Musketeers. Out of these swords of justice, Cobalion is the oldest and wisest and is considered their leader.
- Keldeo, Meloetta and Genesect: The random event trio
- Tornadus, Thundurus, and Landorus - Based on three Japanese gods known as kami, with Tornadus based on Fujin, the god of wind, Thundurus on Raijin, the god of thunder, and Landorus on Inari, the fertility god. Landorus is the master of this trio.