[Tutorial:PKHeX] How to Gen Legal/Legit Pokémon for Beginners (2023)

How to create legal Pokémon with PKHeX for beginners​

Section I: Main

I am not going to go into too much detail regarding exceptions to nature/IV spreads; ball/combinations; Shiny Events, etc after Gen 5. This is to encourage you to do your own research while also giving you specific examples from past generations.

1. Open PKHeX (it will automatically load your current “main” if the directory is present) and drag the “main” file to the open window.

2. Here you will see this familiar window:

On the very first tab, you will see a variety of options. To start, you obviously have to have a Pokémon in mind. For this tutorial, we will create a legal Faraway Island Mew from Pokémon Emerald.
For the species, we are going to choose “Mew” from the dropdown list. Next, we either choose to set a Nickname or not. When creating foreign Pokémon, the name will be changed to the foreign one. If you want to retain your languages name, nickname the Pokémon and check the box.
For this one, we will leave the box unchecked.
For the Exp/Level, you must research the available level(s) at the specific location that your Pokémon can be captured. I suggest using a combination of Serebii.com, Bulbapedia.com and Pokemondb.net.

Since we are making Mew, from Faraway island we can look the information up to see what level he can be caught:

Now we know he is only available at one level; 30.

Moving on to nature. This part can either be extremely simple, or a little complicated depending on if you want your Pokémon to appear legal or legitimate. If you choose the former then it really doesn’t matter what nature you choose; if you want it to look legitimate than you should consider that:

Only 4 natures are possible for 31/31/31/31/31/31 Pokémon caught in generations 3 & 4 (exceptions below). These natures are calm, docile, modest, and timid.

• Wild Pokémon with variable genders (including Heatran) caught in Diamond, Pearl, and Platinum have 7 possible natures for 31/31/31/31/31/31. These are calm, docile, hasty, modest, quirky, sassy, and timid. Wild Pokémon with variable genders caught in Heart Gold and Soul Silver have 6 possible natures for 31/31/31/31/31/31. These are calm, docile, modest, quiet, sassy, and timid.
• Shinies obtained through the Pokeradar in Diamond, Pearl, and Platinum can have any IV/nature combination.
• Wild Pokémon (excluding Legendaries) from Ruby, Sapphire, Fire Red, Leaf Green, and Emerald have 9 possible natures for 31/31/31/31/31/31. These are calm, careful, docile, hardy, lax, modest, naive, rash, and timid.

Now for this Pokémon we will set the nature to “Modest” because we plan to give him a perfect IV spread of 31/31/31/31/31/31; which we know is a legitimate combination.

The held item can be anything except: Game specific items (i.e Blue/red Orb), MegaStones, Z-Stones, etc). The item does not matter if you are not trading the Pokémon.

For the friendship section, you need to know the “base happiness” of the Pokémon you are creating. Again, there are multiple places that you can check to see what the happiness level of the Pokémon is, I like Pokemondb.net.

Here we can see that his base happiness is “100” so we’ll set it to that.

The next section is the ability. Most legendaries only have one ability, for Mew it is “Synchronize”. Even though, PKHeX gives the option of selecting three abilities from the dropdown menu, the third is always considered the “Hidden Ability”. This is something else that requires research. While some Pokémon have their hidden abilities available, a lot of them do not; or only through special circumstances. You must research the abilities of your Pokémon to be sure it can exist in game.

If the first two abilities are the same, you may choose either.

For the language, it does not matter unless you desire to create a specific Pokémon only available to one region as in this tutorial. For Mew, we are going to choose “JPN” and do the same thing for “Country” and “3DS Region” (As mentioned earlier, you will notice the “Nickname” field has been filled in with the foreign name).

Now you should have something like this:

Section II: Met

This is probably the section where people mess up the most when generating Pokémon. I’m not exactly sure why, because it is very straight forward. The first section is the game of origin, which you should know by default when you decided to create your chosen Pokémon. It can get very specific when genning Pokémon with older movesets, or moves only available through tutors from previous generations etc. Again, this is when research comes into play. Look it up to be 100% sure the Pokémon can come from that game, at the level/nature you’ve set.
For Mew, we are going to set the Origin Game as “Emerald”.

The next section is the met location. If you are generating a breeded Pokémon then you will want to set this as any route or town in the GAME you want it to be “HATCHED” in. So, if you chose “Moon” as your origin game, you can select any route or town in Pokémon Moon as the met location. Then, you must check the “As Egg” box near the bottom. From the dropdown menu, on “location” choose Day-Care Helpers. The date MUST be a date BEFORE the met date in the field above. For most Pokémon from previous generations, you will want to choose “Poké Transfer”. The only time this is different, is if you are generating Event Only Pokémon, some of whom have VERY specific locations. For Mew, we will select “Poké Transfer” as stated.

Next it is as simple as choosing the Pokéball for your chosen Pokémon. Regarding legit vs legal, there are some combinations in terms of generations and available pokeballs. This is normally reserved for Dream balls, Apricorn balls in Gen 6, and Beast balls in Gen 7. Since we are creating a shiny Mew from gen 3, it makes sense to me to use a Masterball.

Now you have to set the met level. For ALL breeded Pokémon, this is going to be set to “1”. For everything else, you should be able to copy the level you chose in the previous step. If you are generating a battle-ready Pokémon, then you will want to research to available level of your Pokémon if you didn’t in section I. Following the former, we’ll set Mew’s level to “30”.

The met date really does not have any bearing on legality. You can set this freely, as only Pokémon born in the Generation you are genning for will display and actual date. (i.e. If you create a Gen 7 Pokémon in Gen 7, it will display an exact date). Any Pokémon from previous generations will simply read “…. Has traveled across space and time”. However, for legitimacy we will set our met date to “7/27/2005” when we know the Event Item was being distributed.

The “Fateful encounter” box is reserved for Event Only/Special Pokémon. You will not use this in most cases. Since this specific Mew, does receive the flag for a fateful encounter upon transfer, we are going to check this box.

Your Pokémon should look similar to this:

Section III: Stats

This is going to be a pretty short section as most things are obvious. You can choose to set the IV/EVs yourself specifically, or you can choose to randomize them. Be aware, no Pokémon can have more than 510 EV points total across all six stats and can have no more than 31 IVs. You can also set the hidden power at will, or set all IVs to 31 by holding CTRL and clicking “randomize IVs”. If you would like a specific characteristic, you can follow this chart to set your IVs to correspond to the one you want. For Mew, I will give him 31 IVs in all stats which will give him a hidden power of “dark” and the characteristic “Takes plenty of Siestas”

** As mentioned in section I, if you want the Pokémon to appear legit, you must recognize legitimate Nature/IV spreads for the chosen generation**

The contest stats have absolutely no bearing on legality so feel free to choose any number up to 255 in each stat. Although, for legitimacy sake I will be leaving this section blank.

So, we are left with something like this:

Section IV: Attacks

The attack section is very specific as well. Depending on the Pokémon you chose to create you must take extra care to research the attacks that are available. Attacks can be restricted by generation, level, events and tutors. Pokemondb.com offers a great section of Pokémon attacks based on their respective generation and how they are learned. I highly recommend using it to double check the legality of your Pokémon attacks.

For the example, Mew can learn any move. So, I figured we could have some fun and give him a few sought-after generation three moves. We will give him, Defog, Soft-Boiled, Will-O-Wisp, and Knock Off. Apparently, he is a staller Mew . Since he was born in Gen 3, but is being traded to Gen 7 all moves including and up to the latest generation are available to him provided all the conditions are met.
The PP Up section on the sidebar is completely optional. If you wish you can “feign” the use of PP Ups and give all your Pokémon’s attacks the max PP they can receive.

Relearn moves usually include egg moves, or moves learned at a lower level. Sometimes Pokémon (especially Event/Special Pokémon from previous generations) do not have relearn moves at all, so you may leave it blank. If the Pokémon may have relearned moves, you can click outside of the box for the program to populate the fields with suggested moves. For Mew, we will leave this section blank.

Now on to the next section.

Section V: OT/Misc.

The TID/OT information at the top of the tab will be filled in automatically when you load your save file. If it is not, you can click outside the field to populate it, or enter your information manually if you know it. If you are generating for someone else you must use their information in this field, not your own. For Mew, we will leave the field as is.

The “latest handler (Not OT)” section is only used when the Pokémon has been “traded”. That means if it is a Pokémon you received from someone else, or one that you are generating from a previous generation. The name does not matter as this field does not require any TID/SID information. For Mew, we will just put our OT in this field as well.

Markings are either generated by the game itself, or correspond to the generation the Pokémon is from and cannot be changed. Other markings are optional.

The ribbons tab contains all available ribbons in the game. These are completely optional as well and have no bearing on legality. NOTE: Event specific ribbons will prevent your Pokémon from trading through Wi-Fi; They will trade through direct Wi-Fi trades (If the Pokémon is legal with the ribbon) otherwise ALL Pokémon will trade via local. Since we want Mew to be legit as possible, we will not be using Ribbons.

Medals have no bearing on legality. These can be chosen freely. Though I would advise caution when choosing medals not available in current generations on current generation Pokémon.

Memories are something you normally do not have to mess with unless generating a Pokémon from scratch. Here, if your Pokémon is traded, the “Memories with OT” tab will be greyed out while reading “The Pokémon seems to have a good memory”. In the next tab “Memories with: Not OT” the top option “Memory type” depends on how the Pokémon was received. For traded Pokémon, choose the option “{0} became {1}’s friend when it arrived via Link trade at {2}. {4} that {3}”. Then for the area you may choose “somewhere” if unsure, or “Pokémon Center”. For the next section of “Intensity” just leave the default “The Pokémon Remembers”. And for the last section “feeling” you may choose what you desire.

Finalizing the Creation

Now return to the first tab called “Main”. At the very top you will see “PID” with a grey button next to it called “reroll”. Click this button, if you choose to make your Pokémon shiny, you may also click the “Star” icon to the left of the PID.

After rolling the PID, return to the last tab “OT/Misc.”. At the very bottom, you will see “Encryption Constant” with a grey button called “reroll” and a number similar to the PID. You must click this as well, then for a final time, return the “main” tab and reroll the PID once more to ensure it matches the new encryption constant.

And that’s it! You should now have a 100% legal Pokémon as recognized through PKHeX and of course the game itself! Have fun Genning!!

CREDITS: @Kaphotics for PKHeX, Bulbapedia.com and pokemondb.net.

If you appreciate this tutorial, I appreciate a coffee

EDIT: With recent updates to PKHeX legality involving PID/Nature/Encounters/IV with Pokemon in Gen 3/4/ generating these pokemon from scratch will ALWAYS result in an illegal pokemon as read by PKHeX. The pokemon are still recognized as "legal" by the game as it does not take PID into consideration when determining legality once transferred to Gen 6/7.

However, if you would like them to appear as legit as possible I would recommend using RNGReporter. This will allow you to retrieve a legal spread from your assumed RNG seed target pokemon to use in PKHeX. Alternatively, you can actively RNG for these pokemon in these games via emulator and transfer them with PKHeX.
https://github.com/Admiral-Fish/RNGReporter/releases