Sun and Moon RNGing on retail

Tools

Calculator: 3DSRNGTool.
Mystic Timer.
If you want to RNG a shiny Pokémon, know your TSV. Check your TSV via Battle Videos without Homebrew. Check here.
Having the Shiny Charm will increase your chances of hitting the shiny frame.
You may need a video camera to record the clock hands position at the beginning.
1% luck + 99% patience!

Understanding mechanics

"Frame" and "F"

In this guide, a row of 3DSRNGTool results is called a "Frame". If you trigger the battle or receive the Pokémon at a frame number, we say you hit the frame. "F" refers to real time: 1F = 1/60 second, which is the notation in Gen 3 and in Mystic Timer.

Timer setting

You can use any timer that can set two stages independently. The total time span = Pre-Timer Countdown (Part A) + Standby Time (Part B).

Part A: Systematic error caused by loading the game, some edge frame advancements, and human reaction time.
Part B: Time from starting frame to target frame, varying according to the seed and target frame.

Step 1: Set Up Mystic Timer

Preview

We are using Gen 3 Mode of Mystic Timer.

Pre-Timer: in milliseconds. For example, 2133 means 2.133 seconds. For old 3DS users, the Pre-Timer should be around 3100. For new 3DS users, the Pre-Timer should be around 2500.
Target Frame: in F (1/60 seconds). For example, 3600 means 60 seconds. Mystic Timer may not be accurate since it's designed for Gen 3 consoles. This number is different from the target frame in 3DSRNGTool. We need to convert the Gen 7 frame into real time ("F") using 3DSRNGTool.
Lag: in milliseconds. This number adds to the total time.
Frame Hit: in F. When we do calibration, input the frame we actually hit and click update. A new Lag will be calculated.

In summary, the total time span in seconds = (Pre-Timer + Lag) / 1000 + (Target Frame) / 60.

Step 2: Preparation

Prepare a Synchronize lead, some tool Pokémon to help you catch, and a bunch of balls.
Save in front of your target Pokémon or the person who will give you the Pokémon.
- For legends in Wormholes, stand as close as possible.
- For Mystery Gifts, stand behind the delivery man in the first PC (Route 1) to minimize NPC numbers.
- For wilds and roaming UBs, stand at specific spots with the least NPCs.

Step 3: Set up 3DSRNGTool

In the upper right, input your game version and TSV. If you have the Shiny Charm, check the Shiny Charm box.
Set the Pokémon you are RNGing for.
- For Stationary or Wild encounters, choose the "Category" and select the "Pokémon".
  
  In most cases, you don't need to change other settings, like delay. Some RNG noise can be absorbed in Pre-Timer.
  
  If battling UBs in Ultra Wormholes for the first time, choose "UB (first Encounter)". It’s not recommended because of inconsistent delay.
- For Mystery Gifts, change the "Event Setting" area according to the event you are RNGing.
  
  You can find the WonderCard files (a .wc7) here for the event you are RNGing. Drag-and-drop that into 3DSRNGTool to automatically populate the settings.

Step 4: Load your game or soft-reset

Press L + R + Select/Start to soft reset the game.
If you fail, start over from step 0. The initial seed changes when you restart the game.

Step 5: Find initial seed via continue screen clock needles

Check here.
When you get one seed result, the tool will update it in the main window. The starting frame in the Time Calculator will also update (417/477 + number of frames you saw for clocks).
Double check your seed; most failures are from wrong seeds.
Do not enter your save yet.

Step 6: Find the target frame to hit

Set up your filter preferences.
- "Safe Frame Only": This box appears for non-zero NPC cases. Recommended for initial pre-timer calibration.
- "Blink Frame Only": This box appears for zero NPC cases. These frames can survive for around 1 second and are easy to hit but are rare.
Set a reasonable Frame Range, right-click on the frame you want to hit, and click Set as Target Frame.
- The Gen 7 Main RNG Tool will update this simultaneously.

Step 7: Calculate waiting time and set up timer

Go back to the Gen Main RNG Tool. In the bottom right, everything should be updated. Click Calculate.
A message box will pop up with "Set EonTimer for XXXXF. (YY.YYs) Z". Set XXXX as the Target Frame of Mystic Timer. Z is how long this target frame will exist. For Blink Frame, it should be above 30.

Step 8: Press A at the continue screen, start the timer at the same time

Wait at the final screen until the timer ends. Stay focused!

For gifts or battles triggered by pressing A, proceed to the final screen as soon as possible.
For battles based on one step, open the X menu to freeze character movement.
For wild encounters triggered by Honey, open the X menu and hover over the Bag.

Step 9: Trigger the battle or receive the Pokémon once the timer ends

Press A to trigger the Pokémon Generation.

If the final input is a step, quit the X menu ~2-3 seconds before the timer ends and push the circle pad hard when the timer ends.
If you are doing wild encounters, use the Honey item. Don’t rush, since the RNG will stop in the Bag.

Step 10: If you didn't get the Pokémon

Adjust the Pre-Timer and restart from step 3.
Check Using Stats, input the stats of the Pokémon you got. Check +-100 frames in RNG Info, click Calculate again to see the frames that have the spread you hit. If you can't find the Pokémon, ensure you got the initial seed right.
Check your pre-timer. Look at the Shift/F column.
- If the number is between -4F and 4F, you are doing well, just some bad luck. Start over to find a good seed and hit frame clusters with the same spread.
- If the number is way off, like +12, you hit the frame too late. Adjust the timer two ways:
  
  Decrease your pre-timer: + 12 / 60 * (-1000) = -200, add that to your current Pre-Timer.
  
  Put Target Frame + 12 into Frame Hit, click "Set Timer", and Mystic Timer will do the math and subtract 200 from Lag.

Note: The Pre-Timer calibration is key for Gen 7 main RNG. You may need to recalibrate the Pre-Timer when changing the RNG target.

Additional notes

QR method

This is a variation of the basic steps. Sometimes, we want to hit a high frame number for perfect IVs and shininess. We can consume many frames in Festival Plaza or Hau'Oli Shopping Mall first. Then, check what frame you are on via the QR Scanner, since QR scanner needles also use numbers generated from main RNG.

Preview

Go to Gen7 Main RNG Tool, check Locate Current Frame via QR, input the estimated current frame range, and input the needle sequence until you get a result. The Starting Frame of the Time Calculator will also be updated. So for Step 4, press B to quit QR Scanner and start the timer at the same time.

Note: This method reduces system error of the timer with long time periods.

Measuring NPC count

If results are far from your target, NPC count may need adjustments, especially for Xurkitree, Magearna, and wild standing spots. To check NPC count, change it in the Time Calculator to see which number gives the closest actual time you waited. Alternatively, wait a fixed amount of time and use the QR method to check how many frames were consumed.

Xurkitree

The NPC number changes between 1 and 2 every 10.7 seconds due to wandering Xurkitree in the background. Use the X menu to freeze the varying NPC count. Here's the mindset:

Save while standing behind it for a longer time window for 1 NPC (~7 seconds).
Find the initial seed, load the game, and open the X menu as soon as possible.
Use QR needles to measure NPC count to ensure there is 1 NPC.
- Close the X menu, wait several seconds, and reopen it to refresh the background situation.
Wait with the X menu open to get close to your target frame.
Quit the X menu and trigger the battle quickly to avoid NPC changes.