Pokémon Red and Blue / GAME HISTORY

Why Does Focus Energy Reduce Critical Hits in Pokémon Red and Blue?

A turn spent preparing for critical hits makes them less likely in the original Game Boy battle calculation.

By Patchlo Editorial Desk · Published October 26, 2026 · Sources checked October 26, 2026

Scope: Original Game Boy Pokémon Red and Blue. Community disassembly and code analysis; not modern critical-hit rules.

Spend a turn, get fewer critical hits

Select Focus Energy during battle and the move uses a turn. Later attacks then go through its altered critical-hit calculation. The player has given up an immediate attack to prepare for critical hits, but those hits become less likely.

This does not mean a critical hit becomes impossible. It means the chance is lower than it would have been without using the move. One lucky hit afterward does not show that the setup worked.

Where the calculation changes

The preserved pret/pokered code branches around a doubling operation when Focus Energy is active, then halves the starting value. Glitch City Wiki compares those two paths: doubling without the move and halving with it leaves a four-to-one difference. That comparison comes from community code research, not a newly issued developer statement.

A later formula did not update the old cartridge

Pokémon Stadium used a different critical-hit formula. It did not change the program on an original Game Boy cartridge. Glitch City Wiki also notes uncertainty about the exact base rate the developers originally intended; the observed reduction is clearer than a claim to know every intended design value.