Cracking Animal Crossing's e-Reader Cards

The e-Reader returns as the key to unlock a bunch of unused and broken items. It’s now easier than ever to abuse custom e-Reader cards both on real hardware and on emulator!

e-Reader Character Card Creator Program:

— Corrections —
• Common UPC barcodes technically do not actually contain pricing data embedded in the print, but rather contain data that points software to a lookup price value stored elsewhere. Some barcodes can store pricing data directly on them, though its not as common. The comparison is just to simplify the concept.

This video was recorded with an HD community texture pack for the game ran through Dolphin emulator. You can find info about this highly detailed, custom-drawn pack here:

Assets and other information were pulled from the Animal Crossing GameCube community megasheet:

🎵 Music credits:
• 10 A.M. - Animal Crossing New Leaf:
• Title Theme - Animal Crossing (Nintendo Sound Selection Vol.1):
• Animal Crossing (Autumn) - Mario Kart 8:
• Timed Minigame - Animal Crossing New Horizons:
• 12 P.M. (Jazz Remix) - Animal Crossing New Horizons:
• K.K. Cruisin’ (Jazz Remix):

0:00:00 Introduction
0:00:33 e-Reader Explanation
0:03:43 e-Reader CCC
0:05:25 Exploiting e-Reader Cards
0:07:11 Unused Items
0:10:11 Conclusions

[Hunter-R.]

The e-Reader Card Creator program is now available to download following the link in the description. This initial version required some workarounds, but development will continue to improve this tool in the future. Thank you!

[fakefakerson]

"Now you too can send you friends a zip bomb in the form of paper airplane corruption disguised as a friendly letter!"

[mikejr]

Dude strolls onto YouTube, pushes the whole community forward, and shrugs it off. What a legend.

[cesmaster]

My stand, 「E 3 C」, can summon e-Reader cards from a 'parallel world.'

[Mogswamp]

This is so insanely cool. Might just have to bust the old e-reader out of the closet to try this out.
Thanks for all you do for this game, Hunter R.

[MrCheeze]

Well, you've definitely earned that "you are a great debugger" message.

Anyway, my mind immediately goes (of course) to wondering whether an e-Reader card can be constructed to achieve ACE. Lots of possible angles of attack... Maybe one of the text control codes (which you've brought up before in the context of Nook codes) are too powerful and allow for memory corruption. Or, maybe at least one of the size fields in the e-reader structure can be set to a very large value.

Or, possibly the most viable approach: Exploiting the compression. The fact that the data is compressed means that you can force a relatively tiny amount of _compressed_ data to decompress into a basically arbitrarily large block of _uncompressed_ data, overflowing whatever buffer they set up for it. Since you can't know if this is going to happen without actually decompressing the data, the only way to protect against this would be if the entire decompression routine contains checks against it.

[SaltedNeos]

This is funny timing, I've been working on a small e-Reader project myself the past couple days, trying to translate some japanese only e-Cards for Pokemon Pinball to English because a few Pokemon are locked behind it.

[Chubby_Bub]

I love the OK! YOU ARE GREAT debug message. It feels so passive aggressive, like "okay, you broke the game, proud of yourself?"

[cactus-mcjacktus]

need to get a Dolphin session with the boys going and start sending each other unhinged e-reader codes.

[momoapples]

There has been so much stuff going on in the AC gamecube community recently. Between Brian creating a ticket system and now you developing this, it's pretty crazy that a game over two decades old is still getting this treatment from fans. I'm excited to see what's coming up in the near future!

[garrettchandler]

This would be pretty cool as a present.
You right an actual letter to a friend with one of these custom cards they can scan and they can get a letter and present from you in game. It would be a fun thing to put in a Christmas card.

[ewwstraightppllol]

As someone with ADHD who tends to do niche stuff like this from time to time, your tool is absolutely NOT in vain or a waste of time!!! I wish more people with knowledge would do stuff like this. ;)

[DMP]

This opens many possibilities, not only for population growing, but for any game that actually uses e-reader cards. With some tweaking, this program could do some amazing things.

Thanks for making this, Hunter!

[RyanDxxx]

I was lucky enough to have a uncle who'd do work all around, but did a few jobs in Japan, and I remember him bringing me back a few E-Reader card packs, and a japanese gameboy advance, just so I could play Mario Bros Advanced 4 levels. Unfortunately, was never able to use the e-reader for Pokemon nor' Animal Crossing as well... it got discountined before it came out here cause it wasn't selling well. However, I still have such fond memories of it and think the e-reader was still somewhat underutilized and overshadowed

[Haydunk]

The work on this is absolutely insane, thanks for sticking to such an intriguing niche, this will be so good to mess around with!

[walkthroughvinny]

Thank you so much for providing the source code! As a student software developer it's so fascinating to see C# especially be used in something I absolutely adore.

[MyTablet]

Was the "acnl-4-2024" a hint for new videos this year covering Animal Crossing New Leaf? If yes was that very clever and great video as always!

[blue_bach]

i don’t even have any way to use your e reader card program, but i wanted to say it’s super cool that you made it and awesome that it’s free. been loving your videos; keep it up!

[HannahandCailinLoesch]

It’s crazy how different things were when you were a kid in the early 2000s. The e-reader was probably available to use back when we started playing AC Gamecube at age 7, but since we weren’t on the internet, we accepted it as a mystery and only speculated what it meant whenever we got the message at the terminal in the post office. It’s really cool to learn now, all these years later, about what it actually is!

[sunla]

I'm SO STOKED you made this!! I can't believe after all these years, somebody cracked the code. I'm *definitely* using this. Thank you!!