Bugs:Pokémon Crystal

This page details bugs of Pokémon Crystal.

Since Crystal is basically a souped-up version of Gold and Silver, all bugs that existed in the original games apply here as well unless specifically noted on that page.

Poké Seer glitch

In Crystal only, for every Pokémon the player catches, the game records the level the Pokémon was caught at, its location, and the time of day. This is used by the Crystal-exclusive Poké Seer NPC, who will retell this information if you show her one of your Pokémon.

However, the game condenses the level and the time of day into one byte, where the upper two bits represent the time of day (Morning/Day/Night) and the lower six bits represent the level. As such, this feature will only work correctly for Pokémon up to Level 63, and any Pokémon caught at a level higher than that will have their data overflow into the time of day bits and display incorrect information.

Note that Crystal, unlike Gold and Silver, does not have any wild Pokémon at levels higher than 60, so the only way this glitch could be seen legitimately is by one of the event Pokémon which were released at the time of Crystal's release, such as the Level 70 Shiny Mewtwo available at Pokémon Center New York.

Ho-Oh bug

In Crystal, Ho-Oh can normally only be encountered if you caught all three legendary beasts, and they were not traded from outside. However, the check for this only checks the first five letters of the player name, so even if the last two letters differ (and the name and ID are otherwise identical) the Pokémon will be treated as your own. The relevant code was never adjusted from the Japanese version, where player names were limited to a maximum of five characters.

Clair TM24 bug

In Crystal, after completing the quiz inside the shrine at Dragon's Den, Clair will give you the Rising Badge, and then, once you step out of the shrine, she will also give you TM24 (DragonBreath). If you cannot receive the TM at this point due to the bag being full (this requires sending 99 copies of TM24 as held items from another game, an extremely unlikely scenario), you can return to the gym at a later point and Clair will give it to you there instead.

However, by whiting out inside the shrine from having the last Pokémon faint to poison damage, after completing the quiz and receiving the Rising Badge but before leaving the shrine, it is possible to receive TM24 twice. Clair will give you the TM in her gym, and then she will appear a second time and give you the TM again if you return to the Dragon's Den and step in front of the shrine. This appears to be a simple oversight where the developers didn't consider there would be any other way to leave the shrine than by using the door, so the flags are not properly set to handle this situation.

Notably, in HeartGold & SoulSilver (which uses Crystal's version of the Dragon's Den), it is possible to leave the shrine at Dragon's Den by using Dig or Escape Rope, and in those games the flags are properly set for this case.