Types of game freezes
Softlock (Lock-up)A softlock, or lock-up, simply refers to when the player is stuck in a loop, either with the controls not responding or, for example, being infinitely forced to do an action. Music may still be playing.
Examples: When a óË e Ái or similar Pokémon in Generation III is sent out. When the player triggers a glitch battle system in Pokémon Red, Blue, and Yellow and has a non-usable item in their first slot.
Bar freezeThis is a kind of game freeze often encountered when using a walk through walls glitch. It fills the screen up with mostly full vertical bars, some interrupted with seemingly random letters and numbers.
When this freeze happens, many memory addresses are replaced with '00 39'. (More information can be found here)
Example: Stepping into the first column of 'grass' tiles east of Pallet Town.
Black screen freezeWhen the game freezes this way, it will switch to a black screen. Music often freezes on the note it was playing when this freeze happens.
Example: Can appear when the player uses returns to the overworld after using the Explorer Kit in an invalid area through accessing a 'void' in Generation IV. This phenomenon is also referred to as a 'BSoD' (Black Screen of Death) in the Hall of Origin community.
White screen freezeWhen the game freezes this way, it will switch to a white screen. Music often stops completely when this freeze happens.
Example: When the player uses the dokokashira door glitch in Pokémon Red/Green to enter a location which does not exist.