In wild Horde Encounters, all Pokémon are usually of the same species, but in some cases, one of them may instead be a counterpart or a similar Pokémon to the majority. The Pokémon in hordes are at approximately half the level of other Pokémon in the area and may be a lower evolutionary stage of a Pokémon that normally inhabits the area (such as a horde of Geodude occurring in areas dominated by Graveler). Pokémon encountered in hordes may also have their Hidden Ability. Some Pokémon can only be found in hordes.
Not all locations have wild hordes, but where they exist, hordes may be randomly encountered at approximately a 5% rate in tall grass or flowers (but not in long grass in Pokémon X and Y) or in caves. Horde Encounters can also be purposefully initiated by using Honey or Sweet Scent; however, in Pokémon X and Y, Honey and Sweet Scent will not cause a wild encounter if the overworld weather is not clear. As in all wild battles, a Trainer cannot throw a Poké Ball unless there is only one wild Pokémon remaining. In Pokémon Omega Ruby and Alpha Sapphire, while Horde Encounters can be forced at any time with Honey or Sweet Scent, they only otherwise appear in long grass.
The player's moves in a Horde Encounter act as if the player was in the center of a Triple Battle, except with all five other locations being treated as opponents instead of three opponents and two allies. Moves that target multiple Pokémon simultaneously (like Rock Slide and Surf) are able to strike all five Pokémon at once.
If a mixed horde consists of Zangoose and Seviper or Heatmor and Durant, the different species will direct attacks at each other instead of at the player's Pokémon if possible. The exception to this is moves such as Leer that cannot target allies. Once all the Pokémon of one species have fainted, the horde will begin attacking the player's Pokémon.
In contrast to Triple Battles, Pokémon attacking each other in a horde have no range limit; a Pokémon in a far-left position can attack a Pokémon in a far-right position.
Trainers with a PokéNav by their names will be registered in the Trainer's Eyes or Match Call function after the first battle, and may have a rematch with the player with higher-level Pokémon.
Ash being attacked by a flock of Spearow
In Pokémon X and Y, if the player selects a move that targets an adjacent ally, the user's spot is not highlighted, while the spots of the two opponents in the places where the Pokémon allies would be in a Triple Battle are highlighted as if either of them could be targeted (even if those Pokémon have fainted), despite the user being forced to target itself.
In Pokémon X and Y, if the player selects Acupressure or a move that targets the user and all allies, the user's spot and the spots of the two opponents in the places where the Pokémon allies would be in a Triple Battle are highlighted (but not joined) as if any of them could be targeted (even if those Pokémon have fainted), despite the user being forced to target itself.
Although Horde Encounters have not been a feature of gameplay in the series until Pokémon X and Y, several instances of battles with similar circumstances had occurred or were invoked in the anime since the very first season. Such instances include: