IF YOU'RE NEW TO CORRUPTING, DON'T START HERE.
These are the steps to get DS corruption working properly, and avoid issues with corrupted save files
Most games will still not work. In addition, good results can be tough to come across, so be patient.
This step is only necessary if the game autosaves, or if you do not want to hold onto any saves you may make. For a game like Tomodachi Collection, where all saves are made manually, skip this step. I use an upscaled version of Desmume when I corrupt, available here: (https://www.dropbox.com/sh/7frnn1vlbl6z ... lE6ua?dl=0)
You can use any version of Desmume you want though.
1: Open up DESMUME and then click "Config" at the top.
2: Click "Path Settings"
3: Go to the text box below where it says "SaveRam" and make the box blank.
4: Press OK.
What this does is it wipes the save file path for the emulator, so that no corrupted saves are created. If a DS game detects a corrupted save, it will attempt to delete the save and often get stuck doing so, so you want to avoid creating them if you can.
For games like Tomodachi Collection, you'll be fine as long as you don't manually save the game while it is corrupted. For that game in particular though, and any other game that detects resets without saving, you'll want to save the game, shut off the emulator, turn it back on, and make a save state on the start screen. Load this every time you start the game, corrupted or not (unless of course you want to load a state that takes you to a different part of the game). If you save the game again, make sure you replace the start screen state with an updated one. Make sure you don't load old states as well, as this will revert the game to the amount of progress made when you made that state. You can undo this by loading the newest state you made.
This is done because games like Tomodachi, and other games, detect when you turn them off without saving, and will punish you for this if you do it too many times.
Some games will also display a stop screen if they detect that the checksum is off in any way (ex: Contra 4). With some games, you can circumvent this by putting a save state past the checksum point, and in other games, it does this constantly and you're pretty much screwed.
It's also worth noting that the "+" and "-" keys are for fast foward and rewind, and to use your mic for a game like Nintendogs, you go into Config>Microphone Settings.
To find a good DS rom, you're looking for something not too late after the DS's launch, with a file that isn't huge, with a minimal amount of AI on the screen. Games like Nintendogs, where there are three dogs on the screen at a time, work much better than games like Madden NFL 05, which has over 50 3D AI on the screen at once. Additionally, the larger the better. For example, you'll get much better corruption out of a game like Splinter Cell than you will out of Sonic Chronicles, despite both being 3D. This rule doesn't apply to 2D platformers with 3D characters. 2D games, isometric 3D games, and anything without a main character or object, such as a puzzle game, will not work well. Some games will just not work for no reason at all, don't drive yourself crazy over it. 150000 is the best estimate for a good start byte. A good way to find a range is to go from that start byte to the end of the ROM, and use the bisection method detailed here:
(http://corruptedbytes.com/vinesauce-rom ... ent-guide/) Use this until the game is somewhat stable, while still giving the desired results. Unlike NES corruption though, I would recommend steps of 50000-100000.
There are three methods to corrupting DS ROMs:
Method 1: Running the game directly without any save states. For this type of corruption, depending on the game, you should be somewhere between 7000 and 20000 for your corrupt every xth byte. Don't be afraid to experiment with these numbers, and adjust if you're getting frequent crashes. Most games will not work with this method, or will produce minimal corruption, so it's not recommended for most ROMs.
Method 2: Creating a save state right before a load screen. Generally, you're looking for a load screen that's short, and if possible, loads only a few models and not an entire level. This isn't possible for most roms, so don't let that immediately deter you from trying one. ROMs that work well with the first method will often work even better with this one if there's a loading screen that meets that criteria. Nintendogs is a good example of this. SM64 DS is not a good example of this, despite the fact that it works with the first method. For this method, a good range is 500-3000 for your corrupt every xth byte. Some games don't follow that range: Madden NFL 05 can work with corrupt every 20th byte.
Method 3: Creating a save state directly where the gameplay starts. This is what you try when everything else fails. It's best to create the save state as soon as the gameplay starts so corruption can still show. Because almost everything has already loaded, the only things that will corrupt are your character and other objects, once they move, music, and later on in a level some graphics, and the ability to collide with the floor. These can be unstable and will crash when you advance to another level. A good range is 1-500 for your corrupt every xth byte. Some games are exceptions to this rule, like Tiger Woods PGA Tour 2005, which runs best at around 3000. To get variations on these, change the "xth byte" for best results.
Rom Tier List:
Great (consistently give good corruptions):
New Super Mario Bros (Method 1)
Nintendogs (Met. 1,2,3)
Super Mario 64 DS (Met. 1)
Tom Clancy's Splinter Cell (Met. 3)
Mario Kart DS
Animal Crossing: Wild World
Good (Consistently gives good corruptions, but lack variety. Worth a look but will lose flavor quickly.)
Catz (Met 3)
Madden NFL 2005 (Met 2, 3)
Shrek 3 (Met 3)
Spider-man 2 (Met 3)
Sprung (Met 3)
Tiger Woods PGA Tour (Met 3)
Mario Hoops 3 on 3
OK (either produce evident, but uninteresting corruption, or can produce good corruption but do that so infrequently that they aren't worth it)
Elite Beat Agents (Met 1, 3)
Shrek Smash n' Crash Racing (Met 1, 3)
Star Wars Episode III (Met 3)
Super Princess Peach (Met 1)
Bad (Either produce minimal corruption, always crash, or detect corruption)
Assassin's Creed: Altair's Chronicles
Cooking Mama 1+2
Deal or No Deal
M&M's Kart Racing
Mario Party DS
Ridge Racer DS
Sims 2 + 3
Viewtiful Joe- Double Trouble
Zelda Phantom Hourglass
Almost any 2D, 3D iso, large game, or game without a main character
The tier list is my personal experiences, not guarantees. If you try this, and find some unique results, post them here. If you have issues with any of this, post about here as well. Posting links to good DS corruptions and screenshots here is also encouraged. This doesn't get posted on that often, so save the link if you want to refer back to it.
Thanks to Ego for helping experiment with some of the games listed, and Vinny for helping make this popular, and Vinesauce as a whole for support.