Fusion is the basis of acquiring new Personas in the game. One can take 2 or more Personas and fuse them together to make a new one. One might think it's random, but there are set rules that determine exactly which Persona you will get. At the start of the game, you only have access to fuse two and three Personas together, but later on in the game, you gain the ability to fuse up to 6.
So, what exactly determines what Persona you will get when fusing? The one factor that is always there is the level of your Main Character (MC); if your MC is lower than the level of the Persona you're trying to fuse, you won't be able to fuse it. Other than that, there are certain rules that are followed with 2 Persona fusion and 3 Persona fusion; there are special Personas that are the result of fusing 4, 5, 6 and even 12 Personas at one time.
2-PERSONA FUSION
When fusing 2 Personas together, you must look at the base levels of the "ingredients," as well as their Arcana; their current levels have no factor in determining the outcome. To determine the Arcana of the result, use the following chart to figure out which Arcana you will create. Once you determine the result's Arcana, you must now figure out which Persona in that Arcana you will get. To do this, take the first Persona's base level, and add it to the second Persona's base level, then divide it by two; find the first Persona in that Arcana that is higher than the number you came up with.
insert 2-Persona fusion chart here
EXAMPLE - You fuse Obariyon (Fool, base level 13) with Sarasvati (Priestess, base level 17 together. Fusing Fool and Priestess will result in the Death Arcana. Adding 13 and 17 together, then dividing by two results in 15. The closest Persona to 15, that is higher than that, is Matador, so your result will be Matador if you fuse the above two together.
Now, there is a special case to consider when fusing two Personas together, which is when fusing two of the same Arcana together. When you do that, you will ALWAYS receive a Persona that is a lower level than the ones you're trying to fuse. For instance, fusing Obariyon and Yomotsu-shikome together will not result in Legion, but rather Izanagi, no matter what.
3-PERSONA FUSION
3-Persona fusion is slightly different than 2-Persona fusion. The first thing you need to do is look to see which one of your Personas has the highest current level; that Persona is going to be the third ingredient in the fusion. Take the other 2 Personas and fuse them together according to the 2-Persona rules; the result doesn't matter, since we only need the Arcana. With the result of that 2-Persona fusion, take the third one (the one with the highest current level) and fuse it with the 2-Persona result, adding up the base levels of your three ingredients and dividing it by 3, then adding 5. What Arcana you get is the result of the 2-Persona fusion Arcana and the third Persona's Arcana, which you can figure out using the chart below. Find the Persona that is the closest to your result, but higher than the number you came up with.
insert 3-Persona fusion chart here
EXAMPLE - You are fusing Obariyon (Fool, base level 13, current level 15), Pyro Jack (Magician, base level 16, current level 17) and Yaksini (Empress, base level 18, current level 19). Since Yaksini has the highest current level, it can sit aside for now. Fuse together Obariyon, who is of the Fool Arcana, and Pyro Jack, who is of the Magician Arcana, to get one of the Temperance Arcana. Fusing a Temperance and Empress (since Yaksini is the highest level) will result in one of the Devil Arcana. Add up the base levels of your three ingredients, which are 13 + 16 + 18. That adds up to 47, so divide that by 3 to get 15.6 (drop any numbers after the decimal point), then add 5 to get 20. Taking a look at the list of Devil Personas, the closest one to 20, that is higher than it, is Incubus (level 28).
EXAMPLE 2 - Changing the current levels of the previous Personas, such that Pyro Jack is the highest one, will result in a completely different Persona. Fool and Empress fuse together to create one of the Death Arcana, so a Death and Magician together will create one of the Fool Arcana (according to 3-Persona Fusion rules). All of the numbers stay the same, since that will never change, but the result of this 3-Persona fusion results in Legion (level 21).
Same Arcana fusion is also special in 3-Persona fusion. If you fuse three of the same Arcana, it will always result in a higher Persona than the one you used in the fusion. For example, using Izanagi, Yomotsu-shikome and Obariyon will result in Legion.
SPECIAL FUSIONS
There are some Personas that can't be fused with the above rules. After 7/10 in the game, you will gain accessto special fusions, which require specific Personas to use as ingredients. The following tables shows which Persona are special ones.
| PERSONA | # OF PERSONAS | REQUIREMENTS |
| Neko Shogun (Star) | 4 Personas | None |
| Tam Lin (Sun) | 4 Personas | None |
| Ongyoki (Hermit) | 4 Personas | Maxed Hermit social link |
| Kohryu (Hierophant) | 4 Personas | Maxed Hierphant social link |
| Yoshitsune (Tower) | 5 Personas | None |
| Black Frost (Fool) | 5 Personas | None |
| Futsunushi (Chariot) | 5 Personas | Maxed Chariot social link |
| Yatsufusa (Hanged Man) | 5 Personas | None |
| Trumpeter (Judgment) | 6 Personas | None |
| Mahakala (Death) | 6 Personas | Maxed Death social link |
| Beelzebub (Devil) | 6 Personas | Maxed Devil social link |
| Lucifer (Judgment) | 6 Personas | Maxed Judgment social link |
| Izanagi-no-Okami | 12 Personas | Special conditions |
