We decided to test this bug with super nova here: kzfaq.info/get/bejne/r9CAgZB4ksfIYZc.html

Dang, wasn't expecting to see my happy accident on your channel. I'm glad that thirty-hour battle with Ruby Weapon was worth something! Props to DynamixDJ for testing it as well as finishing the number table for me.

For more technical context - inside the game’s code every turn both enemy and party members current HP is copied to a new field - let’s say “currentHPforBattleChecks”. When doing various battle checks it is this value that is checked against instead of the true current HP. That would normally make sense because it’s a good idea to make such copy to make sure we always had access to the HP value before it got changed by any other functions. However due to an oversight the programmers set the variable type of that field to be “short”, which means it can store up to 65536 values (2 bytes) and then it overflows (wraps around). And that’s the reason for the bug. When you set Emerald’s HP to 990817 (which is a 4-byte integer value) the top 2 bytes get truncated and you’re only left with the remainder of modulo division by 65536 = 7777.

What!!!! 27 years later and this game just keeps on giving!!! 777

our grandkids gonna still be discovering bugs on this game lmfao

FF VII going "How many times do I have to teach you this lesson, old man?" at anyone who thinks the bugs have all been found.

Pretty cool to see this verified I remember this happened to me the first time i was messing around trying to beat Ruby with Cait Sith's slots. I wasmt really paying attention and Ruby hit me with an attack that fully charged the limit guage and put Cait Sith in critical condition when im pretty sure it couldn't have. Now i know what happened

Thank you for another awesome video. I wonder if the developers ever saw this but just left as is, like many of the bugs/incidental "features", but I'd guess no due to its rarity/conditions. I am sure I have seen Emerald do 7777 once, as played through this many times, but I can't be sure.

No way death!!! Another FFVII discovery in 2024? Keep them coming!!! Ffvii just keeps on giving!!!

Thanks for covering this, it blew my mind somewhat when me and Ninja discovered it. It's crazy that this took so long to be found and documented

For anyone who wants a simple way to determine the set of numbers that result from this glitch: Start with 7,777 Add 65,536 This results in the first term in the series. Add 65,536 to that value. This results in the next term in the series. Continue ad infinitum.

Whoever keeping count of the total number of bugs/glitch in this game, have we reached 7777 yet?

I’m shocked this wasn’t discovered sooner, honestly.

It still absolutely amazes me that for a game thats 27 years old, there's still so many new things coming to light within the recent years

Me, seeing another video about an FF7 bug/glitch: "Video of Death's New Threat Caith Sigh battle playes in my head* There's another one? OH MY GOD!

Chocobuckle....blew my mind...

sick pause at 8:00 where nanaki's hp had reduced to be exactly the same as cloud's during the hp scroll-down

i think the last time i have played ff7 was probably around 2005, yet i still enjoy every little video about this game where some new things are discovered. thx man for delivering the fresh ff7 experience over and over through all those years

IT KEEPS GOING

...(Pauses the video to test my theory) Yep, 7777 is 1E61 hex. So it's only checking the lower 2 bytes and F1E61 also triggers the bug. Neat!

So cool, loved it!

If you set player health to 73,313, presumably it would still trigger with the usual graphical effects?

Big numbers like 7,777 and 9,999 show up so often in video games, I started using the shortened term "Quad 7" or "Quad 9". Down to two syllables from twelve in the full "Seven thousand, seven hundred, seventy seven". Did some quick math, if I am right then both Bizarro-Sephiroth (Main Body only) and Safer Sephiroth should also be affected by this bug, under the following conditions: 1. Bizarro-Sephiroth (Main Body only): if Knights of the Round was used on Jenova SYNTHESIS. 2. Bizarro-Sephiroth (Main Body only): if at least six party members are at Level 99. 3. Safer Sephiroth: if Knights of the Round was used on Jenova SYNTHESIS. 4. Safer Sephiroth: if at least one party member is at Level 99 AND Bizarro-Sephiroth's Head was killed no more than 196 times (lol).

Just out of curiosity but do plan on or is there any opportunity for videos like this on rebirth? Are you guys able to get I to codes etc and just dig around? I'm very curious

It did it for me once, he used air tan storm and dealt 7777 to everyone even tho I had more than 7 materias on two characters. Did'nt think much of it at the time, the number pattern made sense for air tan storm.

I finished a playthrough a few days ago. 140 hours, and seen 7777 exactly one time.

I thought it was going to be some silly mistake like "mod(CurrentHP, 7777) == 0", but of course this being the code of FF VII, the correct answer was insane.

It keeps happening!

4:23 It’s an arithmetic progression: 7777 + n*(2^16) for n from 0 to 15. How does that relate to the bytes?

Before even watching, I knew it would relate to the 65,535 hard cap of numbers in a 16 bit integer, and that the 7777 check would probably happen at every 16 bit "cycle". In fact, I believe I saw Emerald hit 7777 many years ago when he was at high HP and figured it was a weird script issue caused by his HP exceeding the "original" 65,535 cap established by Jenova Synthesis. Similar programming quirks caused by this exist in other games too, like in FFIV on GBA, an ATB bug can cause a script to be ignored against Zeromus that causes him to die at 65,535 damage because that's his "actual" max HP and he needs a script that refreshes it to hit his normal 110,000. Killing him too fast can cause the script to be missed and him to die without refreshing. There are other anomalies that are caused by similar things in other games, although I can't remember them offhand.

Have you checked the new glitches found in ancient forest?

Every day it's something with this game

Please please please give us rebirth materia combos too! - - -Love from random ff7 and 9 obsessed guy from some location I love this game so so much. I love when things come together to be amazing (Sopranos, FF games, sticky buns- so on)

The fact that this game didn’t constantly crash is a marvel. There have been so many documented cases of coding bugs/workarounds/etc. neat.

Well that ended up being exactly what I thought it would be when you described it. (but then I'm a C programmer so integer math is a thing I look at often) Honestly I think this is less a deliberate 'shortcut' choice on their part and more that they didn't even realize they were checking this for enemies when making this formula. Even with hacks you can't get a player's HP to greater than 32767 (because that's the max value for a signed 16 bit integer), so there's really no opportunity to hit this when checking player's HP. Meanwhile enemies getting all lucky sevens is something that practically never happens unless you force it, so I have strong doubts that it was even considered as a possibility by the person who programmed the lucky 7s behavior.

Before I even see the explanation given (assuming there is one) I immediately see that the "random" health given is the same value as lucky sevens but with an additional character in front in hex. 0x1e61 vs 0xf1e61 so I assume this happens with any 32 bit value where the smaller 16 bits equal the value 0x1e61 with any value in the larger 16 bits. Guess now I watch the rest of the video :P Edit: Yeah it was that but that's pretty funny. I don't think this is even so much a case of cutting corners, but something that was overlooked during development. The fact they only check 16 bits makes me wonder if they had originally intended for no enemy to have more health than can fit in a 16 bit value, then this was changed later during development and the lucky sevens formula never updated to reflect this change.

crazy stuff

How are these things still being found? lol I love it

I love this game

Pretty interesting! Don't suppose there's any way this can be put to cool use for easy emerald and ruby kills? They can't be poisoned for the self inflicted damage right, wondering if any of their attacks could be reflected and if that would count as self inflicted? I would assume no, and no 😂 pretty cool though

Bank in 1998 I wanted to find a way to defeat Emerald Weapon with Lucky 7's. I found that the game would do 64 attacks of 7777 damage before stopping which, in binary is, 1000000. Once the attacks would stop, I'd throw a planned amount of Gil to put him back into Lucky 7's but... remember it not working. I still don't know why.

I'm more than sure that in one of my, well, around five walkthroughs I actually got that at least once while fighting the Weapons. 🤔

Meanwhile, the perfect pause at 7:47 to match Cloud's and Red XIII's HP

This year is the year for ff7 apparently bugs on bugs 🐛

As soon as he brought up the list of numbers I immediately knew it had to do with the game just searching for a binary HP value that *contains* the 16 bit binary version of 7777 at the end (0001111001100001). Anything past the 16 bits probably requires a binary carry variable, and the game code isn't going to check the carry variable.

I would say that FF7 is held together with duct tape, but I think it's safer to say that it's just Duct tape with some ff7 code sprinkled on it.

The code that checks for 7777 HP casts the current HP as a 16 bit unsigned integer before making the comparison.

oh crap NO!! What a nightmare lol

subtracting from each number using the previous one gives "65536". isn't that some kind of integer limit thing in video games? so couldn't these 16 numbers be rolling over into that?

LOL I love it. It just keeps on keepin on. There aint no gettin offa this train we on

Nice great to see that another bug was found. However, we can say technically, it is not a bug. Devs in crunch time just thought they were safe, why spend more time checking (theoretically) unreachable data.

So aside from Safer Sephiroth, Ultima Weapon, Emerald Weapon and Ruby Weapon… would there be any enemies where this “bug” comes up? Honestly, I suspect it may have been a happy accident or feature rather than an shippable bug

Wow FF7 oh still givin and will again

This just happens 2 month after final fantasy 7 materia duplication glitch.

The math on this seems to be 65,536 x (any whole number) + 7,777

The first time I saw a boss doing 7777 damage other than materia keeper was in a video calmled "FF7 7777 Demons Gate.... INSANE Lucky 7 Speedrun RIP", demon gate got 10 000 HP so yeah it's obvious that it could happen but the odds of him going down to 7777 is pretty low when you are just trying to kill it.

I have a followup question, if someone sets sephiroths hp to one of those values and he does super nova, would it be possible to kill you? Or does it always do % damage anyway.

To beat the underwater weapon, my friend and I manipulated the HP up materia to get Cloud's hp to 7177, then equipped one more HP materia to raise the max to over 8000. Used 5 potions to get to 7677 and right at the start of the battle we used 1 more potion to hit 7777 and that was that.

I always remember when I first played I somehow got tifa to have 7777 hp so any time I would heal her to full it would trigger. I have no idea how I did this.

I've never had anything this interesting happen to me while playing FFVII. I think I've only seen Lucky 7's happen once against a weak enemy that died instantly.

I've had this bug happen to me a long time ago but I didn't think that it was that important since I was a dumb and ignorant child :o

Would you get it if you enter battle with exactly 7777hp but use Aeriths limit to be invincible from damage from attack.

In my MANY years of playing this game, I have only ever gotten lucky 7 UNINTENTIONALLY one single time. And have never seen an enemy get it not even once. It is crazy how unlikely it is

Crazy if this was indeed just discovered considering how much this game's engine has been dissected

Dayum

At this rate, we'll still be discovering and announcing new glitches in January, 2645 (7777 months after it was originally released).

OH NO WHAT NOW

I blame the juvenile Nomura

Holy shit

Isn't there any number below 7777 that matches the first 2 bytes? I do think so. Otherwise, they would not use this lazy shortcut. Nice explanation thank-you

When I see this it triggers some old memories... I swear I had this happen like 20 years ago 😂

First byte = dec97 (hex61) Second byte = dec30 (hex1E) So that makes me wonder if that "611E" is the culprit in the code.

I wonder how many people made Sephiroth trigger the All Lucky 7s state and made Supernova wipe the entire party

Why doesn't Chadley interrupt you and explain?

God dang. Another bug? Lol. It’s the gem that keeps on giving.

This is actually such a hilarious find and one that you would only find by chance like it was. Soon as I saw you pull up the binary code I thought of that office same picture meme. Great find!

As soon as you said there were 16 other values, I paused the video, and thought: - 1,000,000 / 16 = 62,500 - that sounds awfully close to a power of 2 - 2^16 = 65,536 - 65,536 + 7,777 = 73,313 - Lucky 7s must be kept track of by a counter that has a capacity of two bytes (2^16), so it is triggered by a remainder of 7,777. - Each successive value increments by 65,536. Now, the only question is, is there a way to trigger this at 990,817 HP, and then cause the game to somehow grab the value of the two-byte variable that the game uses for HP checks, and use this value to overwrite the enemy's actual current HP? If so, then you would only have to do 9,183 + 7,777 = 16,960 damage to kill Emerald.

What program do you use to edit HP on the fly like that?

Watching death rebirth runs and xenogears and then we got back to this classic... Please keep doing this till we got 7777 spaghetti code bugs 😂

So from 7777 it goes up by 65536 for each other number

I'm inclined to say I've seen this before in a playthrough but didn't pay much attention to it.

This was a pretty interesting find. The coding days back in FF7 days was out of control.

at this point. i wouldn't be surprised if someone finds how to finish the game during the first cutscene. new stuff just keeps getting found.

Awesome little discovery! The chat did have me curious if 77,777 also triggers it (I feel like no, but not sure).

At this point this is the most bugged game in history.

...poor emerald

4:20 It's based off how many bytes of data contain Emerald weapon's HP. Each of these numbers are exactly 2^16 = 65,536 apart. Each bit of data contains a 0 or 1 and a byte is 8 bits. This means that Emerald Weapon's HP is based of 2 bytes of data with second counter that says how many times its cycled through those 2 bytes of data. Each time it cycles through the 2 bytes, the 7777 reader is only checking the value of those 2 bytes of data to see if it's at the 7777 mark. That is, each of these values is exactly k*(2^16) + 7777 for some k. Each k starts a new counter. The 7777 counter is likely set up to only read the 2 bytes of data since that's probably what's used for regular enemies and the characters since very few enemies in the game have more than 65,536 HP, this was probably a convenient way to handle it for almost everything. Only a handful of special bosses and a couple enemies have more than that. There's probably another counter which indicates which 65,536 counter it's on. It's all modular arithmetic from there.

How is this a bug if its done with a mod? Is it a bug in the mod?

Final Fantasy 7 continues being the most broken masterpiece ever. 7777 self damage from Poison due to Lucky 7s, beautiful.

16 chances and yet still I've never seen an enemy hit me with 7777 on any of millions of random play throughs, I must be the most unluckiest player ever :(

It's because the binary sequence is the same-ish 990 817 = 0b11110001111001100001 7777 = 0b1111001100001 Oh you compare it in the video. XD

That's some serious data nerd shit right there

wat mod is he using here?

4:48 what is this pattern? 73951 over and over in the ones column Thanks to guy in chat who pointed out it's modulo 65536 (or five?)

What else is hiding in the code?

🐛 🪲 🐞

Can this make supernova kill you?

I wish I could see the source code for the game, and how atrocious it probably is. As I understand it, the PC port is a cluster****.

A clear cut example of squeezing every coding trick to save on space. Even for the 7777 check.

65536x + 7777 = Lucky 7 x being any positive integral number. Also i love how this game is so broken, people STILL discover things to talk about in this mess of a game code.