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A New World Record For Catching The Original 151 Pokémon Quickly

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Most people never catch all of the original 151 Pokémon in Red and Blue. But one Pokemon speedrunning category challenges players to do exactly that—and without trading, too.

Check out the new world record for catching all of the Pokémon in Red and Blue. It comes in at 2:20:19, and it's performed by Shenanagans Smash, a 21 year old guy from Ohio. The run does make use of glitches—it has to, given that it's impossible to capture Mew in Red and Blue legitimately, even with the ability to trade. Still, it's a fascinating speedrun to watch, since it dismantles the game and shows you what makes it tick.

One of the primary things you have to know about to understand this run is something called "Dsum manipulation." Basically, it lets players control what encounters they get—because it turns out, encounters in the original Pokemon games aren't random, not completely. In order to manipulate what encounters you get, you first need to have one normal encounter, and take note of the species/level of that encounter. Depending on what you get, you can determine how much time you should wait and how many steps you should take before having your next encounter. If done right, the next encounter you have should be whatever you were aiming for. You can read more about the process here, though it's kind of a doozy to take in. Alternatively, you can watch this video, which tells you how to do Dsum:

There are other glitches in this run, of course. The first major one you see, for example, enables Shenanagans to skip the Pewter City gym by saving at the exact right time. Later, you see Shenanagans use something called "item underflow" glitch, which the official Pokemon speedruns website describes as follows:

When you have a stack of 255 of an item and you toss an item above it in your inventory the game duplicates the Item with a 255 stack instead of shifting the end of inventory item up. The game also sees that you tossed an item (even though your inventory is unaffected) so it decreases your item count by one. If you were to toss stacks of candies equal to the amount of items you have the game will think you have 0 items. From here if you have an item removed from your inventory the game will think you have -1 items. Due to the game's use of unsigned integers, having -1 items is displayed as 11111111 (binary), FF (hexadecimal) or 255 items. The game then needs to fill those item slots with something, and it just happens that the "something" it is filled with is pieces of memory. Note that only 128 of the "255" items are accessible because of how the inventory accesses RAM, corresponding to the first 256 bytes from the start of the real inventory (each item uses 2 bytes, one for the item ID and one for the quantity). This gives you access to a decent amount of memory, but not as much as if you actually had access to 255 items.

By changing some of these pieces of memory you can:

  • Warp to different map locations.
  • Get certain items early (like Master Balls, HMs or key items)
  • Change items into other items (usually items with similar item IDs)
  • Change which badges you have.
  • Make text speed faster (0 frames per letter/instant text boxes).
  • Distort the player location.
  • Warp to Glitch Cities for Cooltrainer.
  • Make Instant Glitch Cities for Cooltrainer.

The way this is activated in the 151 run is by making the game think you have 0 items (by tossing the TM29 stacks until you can't toss any more) then having the guard remove a Fresh Water/Soda Pop/Lemonade from your inventory.


You can read more about the glitches used in this run here.

The previous world record in this category was also held by Shenanagans, and that clocked in at 2:23:11—so this new run improved on it by a few minutes. You can check out the rest of the leaderboard here.


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