The Let's Play Archive

Pokemon Yellow

by Crosspeice

Part 34: Speed Run Strats - 151 Speed Run - Part 1

Alright ready for another speed run? Because this time, we're going to go for all 151 Pokemon...

Yes, that's right. There are speed run strats for getting all 151 Pokemon, because that's how insane Pokemon speed runners are. But first...

We have to make sure our Save Data is empty before starting a run. I mean, precious frames could be lost if the game points out that we already have another save file, right?

And of course, there's all the usual rig amoral that you have to do in the Options and Name screens and all that.

And let's not forget this jerk. He gets a stupid name...because he's stupid. And in all seriousness, there IS a reason why he gets this name rather than a single letter one. You'll see later.

HA! Gotchya, stupid /UUUUU! Didn't even need that PC Potion either! (And no, you don't want it. It's not necessary)

You will however want to get these two Potions that are on the way to Pewter. And if you managed to defeat Gary's Eevee (helpful but not necessary)...

You'll want to kill a Lvl 2-3 Pidgey while running around. Helps you to level up to 7 before a crucial fight later.

Speaking of crucial fights...

This Caterpie trainer's a much tougher foe than usual, due to the lack of Nidoran M. We don't really need him like we would in an Any% run, so, you'll most likely have to use a Potion against this guy.

So, be sure to get the hidden Potion next to him if you had to use one.

Now, here's another of the many major differences between 151% and Any%. We're going to be using Pewter City as something of a hub for the first 10-15 minutes or so of the run, and for that, we need to heal with Nurse Jenny...

And then we need to do some shopping, where we should get...

2x Escape Ropes, 10x Pokeballs (9x if you lost the fight against /UUUUU), 1x Antidote.

Alright, time for some grinding...

Now, this next guy's pretty tough...we're gonna want to save, because this next part, might be tricky.

And there we go! Turns out Escape Ropes give you wings! But yeah, we just set up a Trainer Fly, and now we want to fight the Jr. Trainer in Brock's Gym. Problem is, we can't use our buttons now, and the game'll crash if we get too close to any trainers, so,

Be sure to approach the Jr. Trainer from this distance.

The next thing we want to do after that is use Growl six times. But, there's just one problem...

Diglett's have an extremely high critical hit rate, and right now, they do enough damage to kill Pikachu with just two of them.

Unfortunately, there's not a lot you can really do about that. You're going to need to get off at least two Growls before you can safely use a Potion, otherwise you'll risk running out of them before the battle ends.

For example, I STILL ended up at only 5 HP, despite the fact that I had only used a Potion after two Growls. This here is why we beat up a Pidgey on the way here. Eevee and that Lvl 10 Caterpie fall just short of getting us to Level 7, so that random Pidgey is what pushed us over the top. But if you didn't beat that Eevee? Well then, you can skip that step, because you'll end up at Level 6 regardless.

Now, what'll we get?! Why, we get a...

...Level 1...Gengar...yay :eyebrow:?

Well, at least he won't be doing anything with Night Shade or Lick. Good thing too, because Thundershock CAN actually OHKO him if we get an unlucky crit.

And even if we make it through that, Gengar's still got a pretty low catch rate. For reference, it's 45, which means that even though I damaged it, I still only have a 17% chance of catching it with each Pokeball.

But, catch it I do! And now we can move ON with our run!

"So, wait a minute', you might ask. 'Why the heck did we get it at Level 1? If we had not used Growl on Diglett, we would've gotten him at Level 7 instead! So what gives?!" Well...let me give you a hint.

See his stat screen? Seems normal enough...until you see how much Exp. he has. So, a brief aside on Pokemon Exp. formulas and something called "unsigned numbers". There are four kinds of Pokemon in this game as far as level ups go. There are Pokemon in the Fast group, Pokemon in the Medium-Fast group, Pokemon in the Medium-Slow group, and Pokemon in the Slow group. And each one goes by a formula in determining how much Exp. they need in order to reach specific levels. So, let's assume that "N" represents what Level we're looking up as we look at the formulas for all four groups. We have...





Now, one thing you will notice is that the Medium-Slow group is the only one to use subtraction. Normally this wouldn't be a problem, but you'll notice that Medium-Slow Pokemon literally need -54 Exp. in order to be at Level 1, and yet, need 9 Exp. in order to be at Level 2. Now, that's bad enough, but wait, it gets worse. See, this game uses unsigned numbers. What are unsigned numbers? Well, essentially it means it can't properly read negative numbers, which means that if something is reduced to below 0 in this game, the game will use a formula to convert it to it's respective unsigned value. The exact formula it uses depends on whether we're using an 8-bit number, a 16-bit number, a 24-bit number, or a 32-bit number, and in the case of Exp. points, the game calculates them with 24-bit numbers (which can also be called 3-byte numbers). So because it uses 24-bit numbers, it uses this conversion formula...

2^24 - <the absolute value of whatever your number is>

So in this case, we get...

2^24 - 54 = 16,777,162 Exp. points (except, the stat screen doesn't have space for more than 6 digits, so Gengar's displayed Exp. is 777,162).

Now, normally, this still wouldn't result in anything weird. If Gengar gets 63 Exp or more, the game will Level him up to 2, and then re-calculate how much Exp. it thinks he should have based on that. When that happens, Gengar would still end up with a measly 9 Exp. But, if Gengar DOESN'T get 63 Exp or more...this happens.

Yes. That's right. We literally just gained 99 LEVELS BY BEATING A METAPOD !!!

So now, the game is officially broken. It's done. The main game has just been trivialized beyond repair. We could literally solo the entire Elite 4 without so much as a scratch as long as we taught Gengar stuff like Thunderbolt and Psychic. But oh, we're not done yet. For as much as me and CrossPiece have covered this game's glitchiness, we've still only breached the surface. By the end of this update, you'll see that THIS particular rabbit-hole goes down much further than anyone could ever have thought possible ...

Now, back to the RTA. If you've used up all your Potions (and you probably have), but still have some Pokeballs left, you'll want to pick this Potion up. But if you've run out of both of those things, you'll want to wait until you reach the Pokemart in Pewter City before getting anything else.

Whatever your decision, set up another Trainer-Fly on this guy (using your last remaining Escape Rope)

And then commence your grudge match against that stupid Jr. Trainer .

Technically the Jr. Trainer doesn't give us anything in terms of Pokemon, but we need our A Button enabled if we want to talk to Brock. Once we do that...

The next 10 or so minutes just consists of sweep after sweep, with Night Shade being used for Normal types (they're immune to Ghost moves), and Lick for everything else. After that however, you'll want to be careful to follow these set of instructions. Most of them were lifted from the Wiki, then edited by me for further clarification and ease of use. If you want to see them on their native website, here's the link...

There are some VERY significant typoes and omissions near the end, including an entire section on Saffron City that's missing. So keep that in mind.

After beating Staryu with Gengar, MAKE SURE YOU SWITCH PIKACHU INTO STARMIE! After that, do not let him leave until he gets fainted by Starmie, that's critical for this next part.

Once that's done, go to your PC, but DO NOT REVIVE PIKACHU OR HEAL EITHER OF YOUR POKEMON!!. If you do that, you'll completely mess up your warp to Pewter City. Now, once you're in your PC...

Deposit your Gengar, exit out of the PC, take a step to the left...

And then the game'll realize "OH SHOOT, ALL HIS POKEMON ARE FAINTED! TIME TO DIE!!"

And then you'll end up right at Pewter again. Now again, this next step is important as well...

See this Potion? It's on the 6th slot, and the 6th slot is EXACTLY where it needs to be. Be sure to check your menu and see if it's there. And if you happen to have more than one, absolutely BE SURE to toss any extras you have until you end up with just one Potion again. If you're absolutely confident everything's set up right, well...bring up your menu anyway, because this is important.

After that, go back to where you caught Gengar. Exit out of the menu that will automatically pop up, and then...well...this happens.

Yeah...this Missingno is rather infamous in Pokemon Yellow. In all versions, it'll clone 128 copies of whatever item you have in the 6th slot (hope it was a 1x Potion!). But in Pokemon Yellow, it also has a very nasty tendency of crashing your game by messing with your save file. It won't ruin the save file itself, but it will mess up your game in ways that I can't hope to explain, UNLESS your save file is set up in a very specific way. And fortunately, it turns out, erasing your save data before starting a new game will GUARANTEE that you're set up right! That's why we went out of our way to delete our previous save file before doing this run!

Now after that, keep using Growl, and wait until Missingno damages you. Then...

Use a Potion, and let Missingno damage you again, that way you can use yet another Potion. This will bring down your Potion amount to x127. This is important because...

We actually want to catch this guy. And once we do that, we'll get yet another 128 Potions in that same item slot. But if we don't have exactly x255 Potions after all is said and done, we can't do what we want to do.

Also, an amusing aside: Yes, not only is this guy 10 feet tall and weigh 3507.2 LB....but he will LITERALLY be called "Master Ball" when you catch him. I'm not making this up, this is not me being clever, this isn't just a, this Master Ball. His name is Master Ball......

It's a good thing he's earning browny points now, because fricken Master Ball is basically a walking time-bomb in terms of messing you up. See, already the game is freaking out, with a bunch of sprites, like that Channeler sprite, actually walking around on your screen, entirely on their own. But, fortunately, we can get out of this. All we have to do is save our game...

And then do a soft reset.

At this point, I'm actually doing pretty good on time. I'm only 3 minutes off from the world record, but, that'll soon change. If you think this run's complicated now, well, just wait...

For now, the place is still going haywire, so let's go up real quick...

And there we go. Head up to JUST below the door (yes, that's important too), and let's perform the following steps...

Open your item menu:
Swap the item in the third slot of your inventory with Potion
Toss all of the top items in your inventory. This will cause the stack of Potions to duplicate like so...

Now after that, toss the top stack of Potions 3 items (2 if you used your last PokéBall on the Missingno. The Potion's should keep on duplicating themselves).

Then toss all but 2 of the top Potion stack so that your inventory looks like this...

Swap the top Potion with the Potion below it twice. Each time, the two stacks will merge, and...[/b]

BAM! You have Item Underflow!!

You see, even though you're duplicating the stacks of Potions, the game still thinks you're getting rid of an item rather than generating something new. So if you, say, have 16 items, and clone 15 more stacks of Potion x[]5 (255 Potions), the game will still think that you only have 1 item in your inventory.

Normally, this would be detrimental, because the game would then prevent you from going anywhere past Slot 2. And then even when you try to use the stack of Potions from Slot 2, the game would just kick you out of the menu, since it thinks you're clicking the CANCEL button. However, you can still MERGE the two stacks, which will then get rid of one of them. The game then thinks you have 0 items. Then, when you merge ANOTHER two stacks after that, that pushes the game into thinking you have -1 items. And again, the game uses unsigned numbers, but in this case, the game only uses 8 bit numbers to calculate items in your inventory. So, use the following formula...

2^8 - 1 = 255 Items

And there you go. The game actually thinks that you have 255 items now...except, then it scratches it's head and wonders "huh? I thought this guy only had 6 of them?" And in response to that...

It will "fix" it's mistake by dumping something like 240+ of it's memory addresses into your "inventory", allowing you to scroll back the now useless "CANCEL" button in your main inventory. And in doing so, it will also convert said memory addresses into stuff like Badges, HM's, Master Balls, and all sorts of crazy stuff.

What this means is that, if we can mess with all this WITHOUT crashing the game, we can literally rip whole HM's straight out of thin air. We can actually snag ourselves a stack of 128 Master Balls. We can actually CLONE infinite Casino Coins! And, if we really know what we're doing, we can even mess with the game's text pointers. And when we do that, we can literally get into Trainer Battles just by examining items on the ground!

However, the "not crashing the game" part is extremely tricky. For example, if you see a stack of x[]0 Ultra Balls, and you try to swap them out...

You'll end up doing THIS. Because it turns out, that stack of x[]0 Ultra Balls was actually controlling the game's Brightness levels. By messing with that, you've rendered it just about impossible to see what's onscreen. So, once you perform the underflow glitch, you need to be very careful to follow my instructions TO THE LETTER. And, you may want to save your game, just in case you mess something up, because these menus can take a while.

So, after performing that glitch, your menu should look like this. If you scroll down past the CANCEL button, the first thing you see should be something like this...

In order, the items we'll be messing with the most are as follows. Use this as a guide in case you are unsure of which slots to use...

Slots 1-20, normal inventory
CANCEL after inventory
Rival Name
Rival Name
Rival Name
Rival Name
Rival Name (not really Rival Name, but it's what we'll call it)
Map ID
X Position
Warping Master Ball (may be a []x[] item depending on your X Position)
Next couple slots are Map Data
Text Pointer
Next couple slots are Roaming Data

In the roaming data, there is commonly a stack of TMs that have a 198 quantity. 
These will be referred to a lot as the Roaming TMs.  For the most part, items will be consistent, 
so when I say "look for the v_t_m item in the Map Data", just look for that particular item.  
Additionally, if an item has a 0 quantity, the game treats that like 256. 
If the route says to toss 250 of an item with 0 quantity, 
you would want to hit down 7 times until you see x[]0.
And now for your instructions...

Scroll down past a load of []x[] items until you hit some "real" items

Find a stack of []x[] x[]3

Toss 1 from that stack. This will give you the fastest text possible by turning off the frame limiters on it. What this means is that textboxes will go by almost instantly.

Scroll down 7 slots to find a stack of Master Ball x13. It's possible that there is another stack of Master Ball x13 between the []x[] item and where you need to go. Don't touch that one

Toss 8 from this stack of Master Balls to have 5 left

Close your menu...

And then walk out of the building like so...

And WHAMMO! You just warped into Vermillion City! Yes, by being wise about how we manage the "Warping Master Balls", we can actually WARP ACROSS THE CONTINENT! Yay us!

So then, we'll be using Vermillion City as our new hub from now on, so heal your Pokemon here, walk up to your PC...

And save, because this next Underflow menu is going to be very complicated for those who are new to all this. After that, perform the following steps (don't worry, we won't be doing this for the ENTIRE run...)

Open your item PC.

Open the Deposit menu

Scroll down past the []x[] items and find a stack of Ultra Ball x0 in the Brightness slot

Swap the Ultra Ball with the warping Master Ball x5 (down 4). That will cause this to happen...

Deposit 250 Ultra Ball

Scroll up to the TID item (up 5)...

...and swap it up with the []x[] x0 in Rival Name (use the []x[] x2 in the Options menu as a landmark. That's the address we messed with to give us faster text speed)

Scroll back down to the []x[] you just swapped and swap down with the Master Ball x5 below it

Deposit 255 []x[] (yes, this is the same one we swapped with the Master Ball x5)

Scroll up to the Master Ball x5 and deposit 1 Master Ball

Scroll up to the old TID item (up 4) and Swap it down with the X Speed x88 below Roaming Data (below a CANCEL)

Scroll down until you find a Coin Case and Deposit it

Scroll down until you find an Ultra Ball x7 and swap it with a stack of PokéBall x0 below the CANCEL (short scroll)

Scroll down until you find a 6F x19 and Deposit one

Close the Deposit menu and open the Toss menu

Toss all of the top item in your PC 5 times (should be []x[] after two tosses)

Toss all but 2 of the top []x[]

Swap the top []x[] with the []x[] below it twice. Each time, the two stacks will merge, causing PC Underflow

Close the Toss menu and open the Withdraw menu

Withdraw 1 []x[]

Withdraw the rest of the []x[] (yes, we withdrew from the same stack twice)

Withdraw the Coin Case

Withdraw the 6F

Scroll down until you see an []x[] x[]1 (long scroll)

Scroll down a bit further until you see a Full Restore x0

Swap the Full Restore x0 up with the []x[] x0 three slots above []x[] x[]1

Swap the Full Restore x0 with the []x[] x[]1 below

Withdraw 1 Full Restore

Withdraw 1 []x[] in the slot above the Full Restore

Scroll down until you find a stack of Safari Ball (use this as a landmark for the next few withdrawals)

Scroll down and withdraw 255 from the []x[] x0 7 slots below the Safari Ball

Scroll down and withdraw 255 from the Ultra Ball x0 7 slots below the []x[] x1

Scroll down and withdraw 255 from the []x[] x0 11 slots below the Ultra Ball x1. After all that, you're finally done!

Few, that was quite a menu, wasn't it? But, once you exit through the left doormat...

We warp to Celadon now! Next stop...

The Prize Corner!