Pokémon GO Core Mechanics: CP, IVs, Catching and Evolving

Pokémon GO looks simple on the surface, but a handful of underlying systems decide how strong your Pokémon are, how likely you are to catch them, and what it takes to evolve them. Four ideas come up constantly: CP, IVs, catching, and evolving. Here's what each one actually means.

What CP actually is

Combat Power, or CP, is a single number meant to summarize how strong a Pokémon is at its current level. It's calculated from a Pokémon's species-based base stats (Attack, Defense, and Stamina/HP), its individual values, and its current level. Two Pokémon of the same species and level can still have different CP if their individual values differ, which is why CP alone is a rough guide rather than a precise measure of battle performance.

Because CP blends several things together, two Pokémon with similar CP can behave very differently in a fight. A high-CP Pokémon with weak individual values in Attack, for example, may actually hit softer than you'd expect from the number on the screen.

What IVs mean

Individual Values (IVs) are hidden per-Pokémon modifiers added on top of a species' base stats, one each for Attack, Defense, and Stamina. Every Pokémon you catch or hatch gets its own random IVs within a fixed range, which is why two of the same species can feel noticeably different even at the same level. You can check a Pokémon's individual stat bars, and general IV quality, through the in-game Pokémon details screen and Appraisal feature.

IVs matter most if you're investing heavy resources (candy and Stardust) into powering up a specific Pokémon for raids or league play. For everyday catching and casual Gym defense, they're a nice-to-know rather than something to obsess over.

How catching works

When you encounter a wild Pokémon, several factors combine to determine your catch chance: the species' base catch rate, the type of Poké Ball you use, any berry you've fed the Pokémon, the accuracy of your throw, and bonus throw types like curveballs. In general:

• Better balls (Great Ball, Ultra Ball, and similar) improve your catch odds over a basic Poké Ball.
• Berries fed to the Pokémon before throwing generally improve catch odds or reduce how much it struggles.
• Throw accuracy and curveballs reward aiming for the shrinking target ring and adding a spin, which can grant bonus experience and a small catch-rate boost.
• Medal bonuses tied to catching certain Pokémon types repeatedly can also nudge your odds upward over time.

None of this guarantees a catch on any single throw, since there's always some randomness involved, but stacking these advantages consistently improves your odds.

Evolving and candy

Most Pokémon evolve by spending species-specific candy, which you earn by catching, hatching, transferring, or walking with that species as your buddy. Some evolutions also require an evolution item on top of candy, and a smaller set require special conditions, such as reaching a high friendship level with your buddy or evolving during a specific event window. Because these requirements do change and expand as new Pokémon are added, the reliable way to check what a specific evolution needs is the Pokémon's own detail screen in-game, which shows the exact candy cost and any additional requirement.

Putting it together

A simple mental model: CP is the "how strong right now" number, IVs are "how good is this individual," catching is about stacking small advantages on each throw, and evolving is a candy and (sometimes) item investment that usually raises CP significantly. If you're just getting started, our beginner guide covers the basics of a play session, and once these fundamentals feel comfortable, our advanced mechanics guide covers how experienced trainers apply them to raids and battling.

Quick FAQ

Does higher CP always mean a better battler? Not necessarily — a Pokémon's type, moveset, and IV spread all matter alongside CP.

Can IVs change after you catch a Pokémon? Not through leveling or powering up. The two exceptions are trading, which re-rolls a Pokémon's IVs when it changes hands, and purifying a Shadow Pokémon, which raises each IV a little.

Do better balls waste resources on common Pokémon? Many players save premium balls for Pokémon they specifically want, and use basic Poké Balls for common species, though that's a personal strategy choice rather than a game rule.

Ball types at a glance

Ball	General purpose
Poké Ball	The default ball, fine for common species and everyday catching
Great Ball	An upgrade unlocked as you level up, worth saving for tougher or more desirable catches
Ultra Ball	A further upgrade, generally saved for rare spawns or Pokémon that keep breaking out (raid bosses are caught with Premier Balls, which you earn by winning the raid)

Exactly which ball tiers are unlocked at which trainer level can shift as the game is updated, so treat this table as a rough guide to purpose rather than a fixed unlock schedule.

A note on Stardust and candy

Two currencies sit alongside CP and IVs and are worth understanding early. Stardust is earned from most of the things you do anyway (catching, hatching, raiding, completing research, feeding berries at Gyms) and is spent alongside candy to power up a Pokémon, raising its CP without changing its IVs. Candy, tied to a specific species or evolution family, is what's spent to evolve a Pokémon and is also required, together with Stardust, for powering up. Because Stardust is shared across your whole collection while candy is species-specific, many players end up with far more Stardust than candy for rarer species, which is a normal part of how the economy is designed rather than something to worry about.

These four ideas underpin nearly every other guide on Trainer Hub, which is why we'd suggest reading this page before the advanced ones.