Submission #7150: jlun2's GBC Dragon Warrior Monsters 2: Tara's Adventure (Japan) "save glitch" in 28:27.04

Dragon Warrior Monsters 2 is a Pokemon like game, except rather than stuffing creatures into tiny balls, the focus is more on breeding them. Through the use of glitches, this run beats the game within half an hour.

While looking for glitches to improve the currently published run, I found a speedrun video on Youtube labled "Glitchless". Having watched the previous TAS, I was curious on how would RTA folks accomplish such a thing. Looking at Speedruns.com, I discovered that a save bug was used (on console, so it's not an emulation error) to obtain a glitched NPC, that gives you the key to the final boss. After investigating the bug, I decided to make the run.

If you reset on the 1st frame of lag upon saving, the game saves the 1st NPC, but everything else becomes 00. The game however, still believes you have NPCs following you. If you deposit 00 to the farm, the game fails to update the NPCs correctly. Normally, the addresses 0xC6FE, 0xC6FF, 0xC700 (for the 1st, 2nd, 3rd followers respectively) correctly point to CartRam, where information on your recruits are stored. Here's a spreadsheet of every address they point, depending on the values: https://docs.google.com/spreadsheets/d/1bf534qbqoBscz1IvDGdd81DQA0HUIcDw_h3Q-GNYJRI/edit?usp=sharing

Values 0 to ~33 are valid (30 NPCs at the farm, 3 following you, probably more I'm missing). The values correspond to where the game will treat an area in memory as a NPC struct. The struct is as follows: Forum/Posts/506733

However, depositing the beaver NPC when glitched changes the value to 117, which points outside CartRam (0xA000-0xBFFF) and into System Bus. Depositing NPCs reduces this number by 1. A value of 110 has the monster's XP address overlap with my keys at 0xC73F. This means I needed to deposit 7 monsters. Afterwards, I could just obtain at least 1536 XP (or 0x06 00) to change the key ID into the Limbo Key.

The save bug also removes NPCs from screen. In this case, resetting 1 frame before the 1st lag causes the game to not save the NPCs on screen correctly, thus potentially removing them on screen until you reenter said area. This is used to skip the 2nd last boss in game (The one at the bridge).

There's multiple ways for the game's PC (program counter) to jump into 0xC000-0xFFFF area. 1. The "Cloakroom bug", used in the well. Moving to the screen to the right potentially jumps to 0xC000-0xFFFF area, causing crashes. 2. Talking to npcs at the egg area, before you obtain Slime by using "Cloakroom bug" at the well, but instead of going right, go left. The game jumps to 0xD5E1 on dialogue end: https://cdn.discordapp.com/attachments/280808167993245707/840986352761569340/unknown.png 3. Various methods with high index glitch NPCs with save bug, such as viewing their menu, walking around, etc.

I wasn't able to make some GEG occur, but given it jumps to WRAM, if someone can control the bug, credits warp may be possible.

CasualPokePlayer: Changed branch name to "save glitch"... and judging.

CasualPokePlayer: Setting to delayed per author request.

CasualPokePlayer: Well, we can't delay this forever, so I'll proceed with the judgement.

There's a few factors that have to be considered here.

I have noted that the scroll glitch isn't utilized as much as the published movie. However, it's only 2 places, and it saves only a few seconds, so it's not a deal-breaker. Other than that, the optimization is very good. Movie also beats the published non-save glitch movie and the RTA record.

As with all major skip glitches, the legitimacy of the glitch must be in question. I have noted before this movie will desync if played back on new BizHawk versions. This is due to a miscellaneous accuracy improvement, and makes this TAS not possible to console verify. However, this does not affect the legitimacy of the major skip glitch used, since a resync should in principle produce the same result. I have also confirmed the RTA record does indeed do this glitch, and the RTA record is on console, proving this glitch's legitimacy.

As noted in the submission, ACE appears to be possible within this games. However, whether it is controllable and able to trigger the credits (or do anything useful) is not known. Considering the amount of time and effort it would take to research whether both of these could be satisfied, it's not reasonable to demand this looked into.

Considering all this, the movie is acceptable.

Accepting as a new branch for fastest completion.

Zinfidel: Processing...