Spawners contain specific Pokemon and are visible in the overworld. When a Pokemon generated by spawner RNG is knocked out and respawned, the spawner seed advances by 1 frame.

Reaching a desired target involves finding your spawner seed, calculating the upcoming advancements, then advancing the spawner seed until the target has been reached. All of these concepts will be explained later.

Spawner RNG Encounters:

• Uxie/Mesprit/Azelf
• Tornadus/Thundurus/Landorus/Enamorus
• Heatran/Cresselia
• Manaphy/Phione
• Shaymin/Darkrai

Dialga, Palkia, Giratina, Regigigas and Arceus are generated by Main RNG and cannot be manipulated using this method. Custom Firmware (CFW) is currently a requirement if you wish to manipulate any of these encounters.

Required Downloads:

1. LINQPad
   • For running the scripts used throughout this guide, download the latest version and go through the setup instructions.
2. PKHeX Development Build
   • For PKHeX.Core.dll, a requirement for running the relevant RNG scripts. Download and extract PKHeX.Core.dll to a known location on your computer.
3. Libz3 & MicrosoftZ3
   • Other required dll files used for running the RNG scripts. Download and extract Libz3.dll (located in /runtimes/win-x64/native/) & Microsoftz3.dll (located in /lib/netstandard2.0/) to the same location as PKHeX.Core.dll for easy access.
4. Spawner RNG Calculator & Seed Solver scripts
   • The raw scripts used for Spawner RNG, open both of these scripts inside a new browser tab. The calculator is used for predicting upcoming advancements, and the seed solver is used for finding a spawner seed on retail hardware.

You should now have LINQPad properly installed, 3 .dll files inside the same location on your computer, and the two RNG scripts open in seperate tabs of your browser. Ensure everything has been properly followed before continuing to avoid complications.

Figure 1 displays what the Spawner Calculation Script should look like after being configured correctly. To set up the script, follow these steps:

1. Open LINQPad, then change the Language in the header to C# program, delete any extra code that appears after doing so.
2. Find the Spawner Calculation script, then copy and paste all of it into the main window, if done correctly it should look similar to Figure 1.
3. Press F4 to open a sub window, here is where you will add the relevant dll files needed to run the script.
4. In the Additional References tab, add PKHeX.Core.dll by selecting it from files.
5. In the Namespace Imports tab, add a new line at the bottom and type "PKHeX.Core", then close the sub window.
6. Enable compiler optimizations by clicking the small button at the bottom right of the main window, this will optimize search progress.
7. Run the script by clicking the ▶ button, You should now see the script output at the bottom of the window.

If a result appears at the bottom of the main window, the script has been set up properly and can be saved to a known location on your computer for future use.

Figure 2 displays what the Seed Solver Script should look like after being configured correctly. To set up the script, follow these steps:

1. Open LINQPad, then change the Language in the header to C# program, delete any extra code that appears after doing so.
2. Find the Seed Solver script, then copy and paste all of it into the main window, if done correctly it should look similar to Figure 2.
3. Enable compiler optimizations by clicking the small button at the bottom right of the main window, this will optimize search progress.
4. Create a folder inside (or next to) the folder that contains your .dll files, name the folder pa8s or similar.
5. Paste the path for this folder into the correct location on the script (see here for an example).
6. Press F4 to open a sub window, here is where you will add the relevant dll files needed to run the script.
7. In the Additional References tab, add PKHeX.Core.dll, libz3.dll & Microsoftz3.dll by selecting them from files.
8. Copy/Paste the following into the Namespace Imports tab:

Microsoft.Z3
PKHeX.Core
System.Collections.Concurrent
System.Runtime.CompilerServices
System.Threading.Tasks

If done correctly, after running the script, something similar to this message should appear in the output at the bottom of the main window:

DirectoryNotFoundException
Could not find a part of the path 'C:\Users\USER\Desktop\pa8'.

This indicates that the script is working as intended but was unable to find any .pa8 files inside the chosen directory. Information about acquiring the relevant .pa8 files can be found below inside "Seed Information".

To find your spawner seed, you’ll need access to a SysBot. These bots can dump the .pa8 files needed for seed solving without requiring a physical trade, as trading will force a game save.

Many free SysBots are available in community Discord servers—search online to find one compatible with Legends: Arceus.

Using SysBot:

1. Go to the map location of your desired Legendary and manually save.
2. Capture the Pokemon, then return to Jubilife and head to the trade post.
3. Initiate a dump trade with the SysBot, then show it the captured Pokemon.
4. Reset the game, KO the Legendary this time, and advance the spawner seed once.
5. Capture the next Legendary spawn, perform another SysBot dump, and reset again.
6. Download the two .pa8 files provided by the bot (found in private messages).
7. Now you should have two sequential .pa8 files and be back at the correct map location.

Place both .pa8 files in the previously created pa8s folder and run the Seed Solver script to generate a seed, this seed can then be pasted into the Spawner Calculation script to search for upcoming target frames.

Frame advancement methods will differ depending on if your Pokemon is an forced capture or despawns when defeated, this section will cover how to advance frames in both of these scenarios.

Despawns When Defeated:

These include - Tornadus, Thundurus, Landorus, Enamorus, Shaymin & Darkrai.

1. Knockout the legendary, then fly to a campsite.
2. Sleep until night, then sleep again until evening.
3. Fly to a cave and enter, then save and reboot the game.
4. (Optional but optimal) Fly to a campsite then sleep until evening.
5. Fly back to the legendary and wait 1 weather cycle for the legendary to respawn.
6. Repeat from step 1 until the desired frame has been hit.

Note - Tornadus, Thundurus and Darkrai only respawn in certain conditions, Tornadus in a Blizzard, Thundurus in a Thunderstorm, and Darkrai at night.

Forced Capture:

These include - Uxie, Mesprit, Azelf, Heatran & Cresselia.

1. Knockout the legendary.
2. Click through the menus until you regain control of your character.
3. Repeat from step 1 until the desired frame has been hit.

Note - All of these Pokemon are located in caves, with the exception of Cresselia, come well prepared to avoid needing to leave the area.

Unique Cases:

These include - Manaphy & Phione.

1. Knockout the legendary, then fly to a campsite.
2. Sleep until night, then sleep again until evening.
3. Warp to Fire Pit Island and enter the cave, then save and reboot the game.
4. Fly back to the cave that contains Manaphy and wait 1 weather cycle for it to respawn.
5. Enter the cave, check to see if your Pokemon has respawned.
6. Repeat from step 1 until the desired frame has been hit.

Note - Manaphy & Phione are unique cases, they are contained inside a cave but do not immediately respawn. The method used to respawn these Pokemon is more akin to the method used for Overworld.