From Bulbapedia, the community-driven Pokémon encyclopedia.
Tall grass is a mechanic in the Pokémon main series and the habitat for many species of wild Pokémon. By entering patches of tall grass, a wild Pokémon may appear and begin to battle the player.
Tall grass is found on most routes of the Pokémon world, with some routes containing more tall grass patches than others. If the player enters a patch of tall grass, they may randomly enter a wild Pokémon battle. People are warned to stay out of tall grass if they don't have a Pokémon due to the possibility of being attacked by wild Pokémon.
In Generation I and Generation III, if Cut was used, the grass adjacent to the player would be totally erased; in Generation II, longer grass would be gradually cut shorter before disappearing. The ability to use Cut on grass was removed in Generation IV.
Changes between generations
Determining the rate of encounter
The rate of Pokémon encounter is determined from a simple mathematical formula:
1 in (187.5 / ( x )) per step
Let x equal the a value which determines how rare the Pokémon is. The higher the encounter rate, the more common the Pokémon is.
| Encounter Type
|| Encounter Rate
| Very Common
| Very Rare
- Main article: Poké Radar
The Poké Radar is a device introduced in Generation IV that is used to seek out wild Pokémon hiding in long grass. If the Pokémon that is found is knocked out or captured in a Poké Ball, a chain will begin. These chains consist of multiple members of the same Pokémon species encountered one after another. The only catch is this: a player must not encounter any Pokémon just by walking through non-wiggling grass, only by walking into the grass that shakes. Therefore, it is recommended that Repel is used in order to ensure this and achieve a higher chain. Entering the same type of grassy patch the chain was started in that is the farthest away increases the chances of meeting the same kind of Pokémon consecutively. Long chains increase the chance of finding a Shiny Pokémon, which is indicated by the patch of grass glowing white twice rather than shaking.
Some areas in the Pokémon world have larger patches of grass than usual. These patches of grass have grown longer and more widespread than the usual grass patches, hiding many different species of Pokémon. Because of the length and thickness of the grass, it is impossible to ride a bicycle or run through the patches in Generation III, but one can run through them in Generation IV. Some trainers hide in the long grass patches, concealing themselves from view and surprising the player to a battle. Long grass was introduced in Generation II, where it was found in Johto's National Park. In the third generation it was found on Route 119 and Route 120 in Hoenn, and was also present in Generation IV on Sinnoh's Route 210, among other locations.
Seaweed, found only in Generation III, is located underwater in Pokémon Ruby, Sapphire, and Emerald, as an underwater equivalent to tall grass on land. Seaweed can be found while using Dive on dark patches of water on Route 124 and Route 126. The chance of encountering Pokémon in seaweed is lower than that of tall grass.
Shaking grass is found in Generation V, in virtually any area with patches of tall grass. Occasionally a patch of grass can be seen shaking. Entering such a patch triggers a battle with a wild Pokémon. The Pokémon found in shaking grass differ from route to route, but almost all areas contain Tabunne. In some areas, it is possible to encounter in shaking grass the evolved forms of Pokémon found in regular grass.