To find your secret ID, you need to first somehow get a shiny Pokemon whose OT is the Emerald game that you're trying to RNG abuse. Additionally, when you read the instructions for RNG abusing, remember that Kyogre and Groudon are considered "method 1 Pokemon", so you can ignore the stuff about regular wild Pokemon.
You will need to discover the exact IVs of your shiny Pokemon first. Depending on the level, this could be either extremely easy or difficult. Check them with Metalkid's IV Calculator. It may be that the EVs of the Pokemon are unknown, and in this case you will want to use EV reducing Berries to clear them before using MetalKid's IV Calculator.
IV calculator
Once you have found the IVs of your shiny Pokemon, you will need to find its PID. The easiest way to accomplish this is by using X-Act's IV to PID Applet. Simply enter the IVs you calculated above and the nature of your Pokemon. X-Act's IV to PID Applet will then display a list of all possible PIDs based on the information you have entered. For our example, we'll use a captured Fearow with IVs of 6 / 22 / 29 / 17 / 15 / 4 and a Serious nature which was captured in Pokemon Pearl.
Look for output that is similar to the following:
PID: 0466036312 [1BC72658] | Created by Method 1 | Gender Number: 088 | Ability: 0
PID: 4009280062 [EEF8C23E] | Created by Method 2 | Gender Number: 062 | Ability: 0
2 possibilities
Depending on the game where the Pokemon was captured will determine which of these lines you are interested in.
For all Legendaries in every Pokémon game, you will look for PIDs created by Method 1.
For 4th Generation games, you will look for PIDs created by Method 1.
For wild Pokemon in 3rd Generation games you will look for PIDs created by Methods 1, 2, 3, or 4.
Note: There may be more than one line in the output that satisfies the criteria for the Pokemon whose IVs you have entered. In this situation, you will be forced to complete the following steps for both of these PIDs and determine which one was correct at a later time by using Random Number Generator abuse techniques.
PID calculator
Now, you're able to find (a number that's close enough to) your secret ID.
Following along with the sample data from above, we will take the hexadecimal version of the PID (highlighted and in square brackets above), then add as many 0's to the front as are necessary to make this eight digits long.
As our example number is already eight digits, we do not have to pad the number.
Resulting PID: 1BC72658
Our next step is to take this number and half it into two four digit numbers as such:
1BC7
2658
Now open your calculator and convert both of these numbers to Binary. Using Windows built in calculator to do this is quite simple. Select the View->Scientific menu item and then click on the Radio Button next to 'Hex'. Paste in the Hexadecimal number and then click on the radio button next to 'Bin' to switch to the Binary view of this number.
Do this for both halves of the PID and paste the results into a text file.
1101111000111
10011001011000
Once this is done, switch your calculator into decimal mode and paste in your Trainer ID. We will be using 55083 for this example. Click the Radio Button next to 'Bin' to convert this into a third Binary number and paste the results into your text file under the first two.
1101011100101011
The next task is to make each of these binary numbers exactly 16 digits long. If any number has less than 16 digits, simply add enough zeros to the beginning of the number to make it so.
Now these numbers should line up as below:
0001101111000111
0010011001011000
1101011100101011
Our next step is to use these three numbers to create a 4th number, which will be our deduced secret ID.
Our goal when creating our 4th number is to have the sum of the number in each individual column equal either 0, 2, or 4; that is for the number of ones in each column to be an even number. Please note that this calculation is only necessary for the first 13 columns.
The example below shows the math for each of the 13 columns.
0001101111000|111
0010011001011|000
1101011100101|011
-------------|---
1 |000
As the sum of the first digits in this column add up to 1, we will add 1 to get our even result, which is 2 in this case.
0001101111000|111
0010011001011|000
1101011100101|011
-------------|---
11 |000
As the sum of the first digits in this column add up to 1, we will add 1 to get our even result, which is 2 in this case.
0001101111000|111
0010011001011|000
1101011100101|011
-------------|---
111 |000
As the sum of the first digits in this column add up to 1, we will add 1 to get our even result, which is 2 in this case.
0001101111000|111
0010011001011|000
1101011100101|011
-------------|---
1110 |000
As the sum of the first digits in this column add up to 2, we will add 0 to get our even result, which is 2 in this case.
0001101111000|111
0010011001011|000
1101011100101|011
-------------|---
11101 |000
As the sum of the first digits in this column add up to 1, we will add 1 to get our even result, which is 2 in this case.
0001101111000|111
0010011001011|000
1101011100101|011
-------------|---
111010 |000
As the sum of the first digits in this column add up to 2, we will add 0 to get our even result, which is 2 in this case.
0001101111000|111
0010011001011|000
1101011100101|011
-------------|---
1110101 |000
As the sum of the first digits in this column add up to 3, we will add 1 to get our even result, which is 4 in this case.
0001101111000|111
0010011001011|000
1101011100101|011
-------------|---
11101010 |000
As the sum of the first digits in this column add up to 2, we will add 0 to get our even result, which is 2 in this case.
0001101111000|111
0010011001011|000
1101011100101|011
-------------|---
111010101 |000
As the sum of the first digits in this column add up to 1, we will add 1 to get our even result, which is 2 in this case.
0001101111000|111
0010011001011|000
1101011100101|011
-------------|---
1110101010 |000
As the sum of the first digits in this column add up to 2, we will add 0 to get our even result, which is 2 in this case.
0001101111000|111
0010011001011|000
1101011100101|011
-------------|---
11101010101 |000
As the sum of the first digits in this column add up to 1, we will add 1 to get our even result, which is 2 in this case.
0001101111000|111
0010011001011|000
1101011100101|011
-------------|---
111010101011 |000
As the sum of the first digits in this column add up to 1, we will add 1 to get our even result, which is 2 in this case.
0001101111000|111
0010011001011|000
1101011100101|011
-------------|---
1110101010110|000
As the sum of the first digits in this column add up to 2, we will add 0 to get our even result, which is 2 in this case.
This leaves with a final binary number which represents our Secret ID.
1110101010110000
Switch your calculator to 'Bin' and paste in this result and then switch the calculator to 'Dec' to finally retrieve your Secret ID in decimal. The Secret ID in our example is 60080.
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Once your Secret ID has been determined, you must generate a list of shiny spreads using RNG Reporter (see the following section). Bear in mind that the spreads will vary depending on the method that generates them; a great method 1 spread is exclusive to Pokémon generated via method 1, and so on. On the subject of exclusivity, shiny spreads are tied to the combination of your Trainer ID and Secret ID. In other words, if your friend discovers a great shiny spread on his or her game, it will not be shiny on yours, save the immensely unlikely scenario that both your IDs and SIDs are identical (and the even less likely scenario that you actually have a friend).
RNGReporter
Although the goal of this article has been to remove the need to use any external software (by providing comprehensive frame lists in the form of .csv files), it may be useful to familiarize yourself with the tool that was used to create them. Additionally, RNG Reporter has some advantages over the spreadsheets and is necessary if you wish to capture shiny Pokémon. Efficient filtering and the ability to search frames higher than the 100,000 that are included in the spreadsheet are also be useful features.
Before starting you must download and install RNG Reporter. Please pay particular attention to the prerequisites and the installation directions.
RNG Reporter, at its heart, is a tool to predict the nature and IVs when a Pokémon is created on a particular frame. By default, RNG Reporter will show the output of the first 100,000 frames, starting from the first, but is flexible enough to allow you to start at some later point in time. Up to 999,999 frames may be shown at one time. To get the most out of the tool, there are quite a few settings and filters can be tweaked which are outlined below.
Method
The method, which was briefly described above, is used to govern how output from the random number generator is used to create an IV spread. When attempting to capture method 1 Pokémon, select "Method 1". When attempting to capture wild Pokémon, select "Method 2". For breeding, you should select "Breeding (Emerald Splits)". The other options listed on this dropdown are generally used for other games, and may safely be ignored.
ID and SID
When both of these items are filled in with your trainer ID and secret ID, RNG Reporter will be able to mark particular frames as being shiny, or "find your shiny frames". As these frames will be different for each combination of ID and SID it is important that they are entered correctly. Frames which hold shiny Pokémon will be denoted a by the presence of the text "!!!" under a similarly named heading in the output. Once identified, these shiny frames are targeted exactly like any other.
Shiny Only
When this option is checked, RNG Reporter will filter out all Pokémon that are not shiny, leaving you only with those that are. This requires that your trainer ID and secret ID were correctly entered.
Once all of the desired options and filters are selected, clicking the "Generate" button will produce the listing of frames. Once generated, this list can be browsed on screen or output to .csv by right clicking anywhere in the listing and selecting "Output Results to .csv" from the menu. There are a number of other useful features squirreled away in this menu which deserve mention.
Set as Target Frame
This option allows you to tag your target frame and to easily return to it after scrolling around through the output. The current target frame can be determined by checking the "Target Frame" label at the bottom right hand corner of the RNG Reporter window.
Jump to Target Frame
This option will select, and show if it is not currently visible, the frame which you have previous marked at the target.
Center to +/- x Seconds and Set as Target Frame
This option is used to trim the frame output, centering on the selected frame and limiting the output to a certain number of seconds before and after. For example, if your target frame is 1,000 and you select this option (with one second) then frame 1,000 will set as the target and the complete listing of frames will only include those between 940 and 1060. Each second is considered to be 60 frames.
Remove Centering
Using this option will remove any of the frame trimming that is caused by the center function which was explained above.
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If you do this correctly, then the RNG reporter should give you some shiny frames. Please tell me if I missed any steps.