Submission #4280: keylie's SNES Chrono Trigger in 2:17:08.86

Super Nintendo Entertainment System
baseline
(Submitted: Chrono Trigger (U) [!] USA)
Bizhawk 1.5.3
494545
60.0988138974405
24994
Unknown
Submitted by keylie on 4/17/2014 8:19 PM
Submission Comments
After turska and inichi totally broke the game by using mid-frame reset, most of the game's content disappeared from the any% branch. However, this game has a lot of tricks and glitches to show, that's why I worked on the any% while banning any memory corruption techniques.
The overlay was created using this lua script.

Game objectives

  • Emulator used: Bizhawk 1.5.3
  • Aims at fastest time
  • Doesn't use any memory corruption
  • Uses soft resets

Tricks and glitches

Un-equip glitch

Un-equipping stuff is not normally possible in this game, and every character comes up with a full equipment. However, there is a trick to un-equip a helm or an armor under certain conditions. Briefly, it involves changing characters and slots at the same time (e.g. pressing up and R) in the equipment menu, thus confusing the game into thinking you didn't change slots. For this to work, you must have at least one item to choose from the first slot
Un-equipping increases magic attack and magic defense (except against fire). Un-equipping either the helm or the armor gives a magic attack bonus of 10 and lowers magic damages by about 80%. Un-equipping both helm and armor gives a magic attack bonus of 20 and lowers magic damages by about 90%.

Fade-out glitch

By opening the pause menu and leaving it when the screen starts to fade out, you can have a few frames to move in another direct. If you repeat this again and again, you can get to a point that would trigger a certain event, keeping the fade-out status. If you set a flag that determines if the event completed and let the fade-out be done, you are brought to the previous room and it is considered the event already finished. It can be used to skip a few bosses, and also to trigger the save anywhere glitch.

Save anywhere glitch

If you do the fade-out glitch, move over a save point and wait for the screen loading, you will be able to save anywhere as soon as you don't enter a room with a save point. Being able to save anywhere allows you to get past triggers if you save at the right spot.

RNG manipulation

The RNG value is set at the beginning of the game based on the number of frames spent on the save file loading screen. Thus, the RNG can be set to an arbitrary value by saving, soft-resetting and loading the save file at a specific moment. This is the only way to change the RNG outside battles.

Smoothly escaping

An escape counter builds up even when you open the technique or item menu in battle. The thing is, you can escape from a battle without being attacked by setting the battle mode "Wait", opening the either menu and holding the L+R buttons.

Lavos Shell skip (from inichi)

First of all, here are two facts that makes it possible to skip Lavos Shell:
  1. In trying to warp to A.D. 1999, if you somehow open the menu just before the fade-out starts, then the coordinates that Crono will appear at in 1999 are totally the same with where he was at the End of Time.
  2. If that x-coordinate is the same with the Lavos' hole x-coordinate (which is 8) and that y-coordinate is the same with or below the Lavos' hole y-coordinate (which is 8), then the game immediately sends him into Lavos Shell.
The thing is, you can directly access the inside of Shell Lavos if you manage to open the menu at (8,8 or any less) at the End of Time right before the fade-out starts. Of course it is out of the question in a normal manner. First, you lose control of your character as soon as you examine the bucket. Second, (8,8 or any less) is outside the moveable area. To solve the problem, I took the help of another two gates, Bangor Dome gate and Tyran Fortress gate.
Bangor Dome gate was used to change the direction that Crono flies to, and to get close to the needed position. Also, because Bangor Dome gate is the most left below gate out of nine gates, unlike the other gates, a line segment between the bucket and the position Crono flies to contains the upper right corner of the gate floor, a moveable area, of course. This is of great importance after you regain control.
Tyran Fortress gate was used to regain control and occur the second flying action. If you choose "yes" just before Crono starts flying, you can open the menu again. And if you change your party's order twice in that condition, Crono gets out of flying and you can control Crono again. As I said above, the line Crono fly along contains the moveable area. So if you restore the control on that area, you can have Crono run around as usual.
If the other two characters finishes flying, Crono takes the second flying action. Very fortunately, a line segment between the bottom left corner and the position Crono flies to contains (8,8 or 7). And the fade-out starts when Crono passes on (8,8 or 7). So I simply moved Crono to the bottom left before he started flying again and opened the menu on a certain timing. Crono appeared at the same coordinates with Lavos' hole and Lavos Shell skip was possible.

Elixir glitch (from inichi)

Normally, when a character with the Green Dream is defeated, he automatically revives. However, sometimes, he falls down once again and gets up. If that happens, the game temporarily considers him as dead, and if the other two characters are really dead at that point, he becomes unable to use any item on himself. Instead, he is able to use an item on enemies! And if you use an elixir on an enemy and the sum of its current HP and the amount of HP heal is more than 32768(0x8000), that cause overflow and does instant kill. Inner Lavos (20000) and Lavos Core (30000) are only enemies who meet those conditions. Therefore, the glitch is only available in those two battles. Also, there are only two elixirs on the way.

Improvements

  • In general, all fights can possibly be improved, as those are very laggy. It tried to minimise it, but on a 5 minutes fight, perfect manipulation would require an extensive amount of time.
  • Possibly, taking an extra Power Tab might save time in total. This is really hard to guess though. The fastest Power Tab that I skipped takes 10 seconds to take, which corresponds to about 3 physical attacks.
  • I pushed a button on Tyranno's Lair that wasn't necessary (what was I thinking?), loosing about 2 seconds.
  • I removed Robo from the party in the End of Time before visiting Melchior again. Removing him while doing the fade-out glitch in Melchior's home would save about 10-20 frames.
  • It is possible to skip the fight in Truce Canyon on the way back, as shown here.
  • At 1:11:42, it is faster to do the fadeout glitch from the stairs than from the entrance of the house.
  • In the first screen of Lab 16, a better route can be taken from the first chest
  • Improved Medina cake skip by switching party just after eating the cake
  • In Denadoro Mts, save/reset at the top-right corner
  • Use Robo instead of Marle against Masamune (Fire punch is a bit faster than Antipode, also this skips a menu to de-equip Marle)
  • In Zeal Palace, it might be faster to take the left path
  • Improve the setup for the double elixir glitch
  • Manipulate the camera to avoid a freeze in Denadoro
  • Skip one jailbar animation

Thanks

  • Huge thanks to inichi for all the work he has been doing on this game. I didn't want all these discoveries to be buried in the forum, that's why this tas was made.
  • Thanks to ottavino for reviewing my work, and especially for finding a fast setup for the last elixir glitch.
Suggested screenshots: 47220, 187200

feos: Judging...
feos: Cleared the branch. The mid-frame reset run is going to become "SRAM glitch".
feos: Accepting as a new (blank) branch.
Spikestuff: Yaaaaaaaaaaaaaaaay! Publishing.
Last Edited by adelikat on 10/10/2023 2:26 PM
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