After you capture Pokemon, you must battle them to progress through the game. Battling is relatively simple in Pokemon Red, Blue, and Yellow. One Pokemon faces one other Pokemon in a turn-based style battle. That means both sides select a command (attack, switch to another Pokemon, or use an item), and then one side moves before the other. The turn priority depends on the speed of the Pokemon. If an item is used or a Pokemon is switched out, this will occur before a Pokemon attack.
Select one of up to four moves to damage the Pokemon, reduce stats, increase stats, or inflict various status conditions. The objective is to cause the other team of Pokemon to faint by reducing their HP to 0. Each attack has another stat called PP (Power Points). This determines how many times a move can be used. If a move has 5 PP, it can be used five times. Restore PP using an Ether, Elixir, or returning to a Pokemon Center.
All Pokemon in Red, Blue, and Yellow have five different stats. They are HP, Attack, Defense, Special, and Speed. These stats will grow naturally as you battle other Pokemon and gain experience points. That is why trained Pokemon are always stronger than wild Pokemon or newly caught Pokemon. Additionally, stats can be boosted with vitamins found around Kanto and sold at the Drug Store in Celadon City’s Department Store (5th Floor)
HP is short for hit points. It’s the amount of damage a Pokemon can take before it faints. Increase with HP Up.
Attack is the physical damage done to other Pokemon. The following types are physical: Bug, Fighting, Flying, Ghost, Ground, Normal, Poison, Rock.
Defense is the amount of damage a Pokemon can withstand from physical attacks.
Special is both the special damage done to other Pokemon and the amount of damage a Pokemon can withstand from special attacks. The following types are special: Dragon, Electric, Fire, Grass, Ice, Psychic, Water.
Speed is how fast the Pokemon is. The higher the speed, the more likely it can attack before its opponent. In RBY, speed also affects the chance of landing critical hits.
In addition to base stats, there are a couple of stats that only matter during battle.
Accuracy is the Stat that determines the ability to hit a Pokemon. All Attacks have an accuracy stat which ranges from 100% to 30%. The less accurate attacks are usually much more powerful.
Evasion is the Stat that determines the ability of a Pokemon to dodge an attack. A Pokemon’s Evasion can be increased or decreased in battle to evade a Pokemon’s Attacks, just like if you were to lower a Pokemon’s Accuracy.
While in battle all stats, with the exception of HP, can be increased and decreased with certain moves. Each stat can be increased up to six times or decreased up to six times. If one Pokemon’s stat is increased to the max, it can then be reduced up to twelve times to reach the bare minimum. Some stat changing moves can alter a Pokemon’s stats two stages at a time, meaning they only have to be used three times instead of six.