Legends: Arceus RNG (CFW)

A guide for RNG manipulating Legendary & Mythical Pokémon in Pokémon Legends: Arceus using tools developed by LegoFigure11 and Lusamine.
Introduction

In Legends: Arceus, all Legendary & Mythical Pokémon have predetermined internal values that can be predicted in advance using RNG manipulation. Learning how this works allows you to obtain any Legendary/Mythical Pokémon in the game with desired IVs & Natures.

Pokémon are not all generated in the same way. Because of this, the method you use to manipulate RNG will depend on which Pokémon you are trying to obtain. In this guide the Pokémon fall into two categories, "Main RNG" or "Spawner RNG".

RNG Type Distinctions
Main RNG

Main RNG functions as a continuously advancing RNG state. Achieving a desired result requires precise timing of your final inputs just before the Pokémon is generated. This method will feel familiar to those experienced with RNG manipulation in previous Pokémon titles.

Encounters
  • Dialga or Palkia — Origin Form
  • Dialga or Palkia — Non-Origin Form
  • Giratina
  • Regigigas
  • Arceus
Spawner RNG

Some Legendary Pokémon are tied to overworld spawners. When entering an area, these Pokémon are assigned a "Spawner seed". To advance this seed, the Pokémon must be defeated and respawned. Reaching a desired result involves repeating this process a specific number of times until the target outcome is achieved. No precise timing required.

Encounters
  • Lake Trio — Uxie, Mesprit & Azelf
  • Weather Quartet — Tornadus, Thundurus, Landorus & Enamorus
  • Heatran
  • Cresselia
  • Manaphy & Phione
  • Shaymin
  • Darkrai

Information - You should now take the time to decide which Pokémon you want to target and understand which RNG category it falls into. This will determine which of the two methods you use to approach the RNG.

Tool Setup & Installation

Learn how to use and configure the tools used throughout the RNG manipulation process.
Required Software
Tools and Applications
Installation Instructions
  1. Download the latest release of ParLiAment then extract the contents of the download into an empty folder in a known location on your computer.
  2. Download SysBot.NET - Moarencounterbots then extract the contents of the download into an empty folder in a known location on your computer.
  3. Download sys-botbase then extract the contents of the download to the root of your Switch SD card, reboot the console into your chosen CFW environment after doing so.
Troubleshooting

You will need to remove all mods or cheats for Legends: Arceus before proceeding. Mods/cheats can alter the RNG of the games and cause RAM reads to fail. Switch mods/cheats are stored in the atmosphere/contents directory on your SD card. This folder is typically empty on a fresh installation of Atmosphère.

Methods for Disabling mods/cheats

Any of these methods can work to disable mods/cheats. You should select the best one for your use case.

  • Rename the atmosphere/contents folder to something else, such as oldcontents. This will allow you to keep everything you previously installed. You can simply rename the folder back when done.
  • Delete the atmosphere/contents folder. This may be a good option if you have many files in this directory that you do not recognize and you want to clean out your SD card.
  • Delete specific mods/cheats from the atmosphere/contents folder. This requires you to know which title ID corresponds to what.
  • If you wish to keep the atmosphere/contents folder intact, you can hold L every time you boot the game.

Information - A direct download for Lusamine's SysBot.NET fork (Moarencounterbots) is provided above and should work perfectly for the purposes of this guide. If you wish to use the absolute latest commit you must build the project yourself by following this guide.

Figure 1 - ParLiAment Setup

la-legend-1
ParLiAment Setup

When opening ParLiAment for the first time you will be presented with something similar to the above image. Before doing anything else you will need to confirm that you can connect to the program with no issues by doing the following:

  1. Launch Legends: Arceus and stand anywhere in the overworld.
  2. Type the IP address of your Switch console into the Switch IP: field of ParLiAment.
    • Your Switch IP address can be found by launching the Homebrew Menu then pressing the Y button (port is not relevant).
  3. Click the Connect button on ParLiAment. If connection was sucessful you should now see that the Main Seed [0] & Main Seed [1] fields have updated automatically.

Figure 2 - Moarencounterbots Setup

la-legend-2
Moarencounterbots Setup

When opening SysBot.NET for the first time you will be presented with something similar to the above image. By default, SysBot.NET comes preconfigured for the latest available game (which is not Legends: Arceus), so first you will need to change the mode of the bot by doing the following:

  1. Open SysBot.exe then immediately close the program. Doing this will generate a file named config.json.
  2. Right click config.json and open it using your favourite text editor (e.g Notepad), you should see a list of settings that determine how the bot operates.
  3. At the top of the page, search for a setting named Mode and change this to 3 (Mode 3 represents Legends: Arceus).
  4. Save your changes and close the text editor, now open SysBot.exe again. If done correctly you should see SysBot: Pokémon (LA) in the program header (see image).

Great! - You should now have all of the required programs installed on your computer sys-botbase properly installed to your console. Confirm which RNG category your target Pokémon falls under, then click the relevant button below to get started.
My target Pokémon uses Main RNG My target Pokémon uses Spawner RNG