Red/Blue UnderUsed Metagame Primer

• Composition
• Clauses
• Mods
• Restrictions

Composition

UU (UnderUsed) is comprised of Pokémon that were considered definite "not standards" at the time that RBY was the current generation. These Pokémon were ones that were determined to not hold a sufficient enough niche that you would encounter them in a standard OU match.

A list of the current UU Pokémon and those with UU analyses for the RB era are found on the dex page.

Clauses

Players must abide by the following clauses:

• Species Clause - A player cannot have two Pokémon with the same National Pokédex number on a team. For example, you cannot have 2 Koffing on your team.
• Evasion Clause - A Pokémon may not have the moves Double Team or Minimize in its moveset.
• OHKO Clause - A Pokémon may not have the moves Fissure, Guillotine, or Horn Drill in its moveset.
• Endless Battle Clause - In the event of an endless battle (such as only two Dittos remaining who can only transform forever, two Gengar forced to Struggle against each other, etc.), a draw is called.
• Cleric Clause - All Pokémon must have full HP and PP, and not have any status conditions prior to the battle.
• Invulnerability Clause - A Pokémon may not have the moves Fly or Dig in its moveset. This is due to a glitch where a Pokémon that becomes fully paralyzed while in a semi-invulnerable state (the second turn of the attack) will remain in that semi-invulnerable state until switching or using Fly or Dig again.
• Tradeback Clause - Tradeback moves from GSC are not allowed.

Mods

Our simulator has implemented these modifications:

• Sleep Clause Mod - No more than one Pokémon on each player's side may be sleeping as the direct result of an opponent's move. All effects of moves that would cause sleep are prevented from taking effect while Sleep Clause is active. For cartridge players, you lose if, at the end of your turn, two of your opponent's Pokémon were put to sleep by a move you used, but were not forced into, and neither have had their sleep removed since then.
• Freeze Clause Mod - A player cannot freeze two of their opponent's Pokémon at the same time. All effects of moves that would cause freeze are prevented from taking effect while Freeze Clause is active. For cartridge players, a player has the option of requesting a redo or playing it out in the case of receiving multiple freezes.
• Desync Clause Mod - If a move would cause a situation that leads to battles desynchronizing during a Link Battle on cartridge, the move will fail. For example, in the event Psywave would deal 0 damage on one side and 1 damage on the other, the move will fail.

Restrictions

The following are not allowed in the format:

• Banned Pokémon - A team cannot have any of the Pokémon found in the following tiers: Uber, OU, and UUBL.