> For the complete documentation index, see [llms.txt](https://docs.x.ar/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.x.ar/persona/utilities.md).

# Utilities

There are 9 rarity levels of Personas. Each rarity level of Personas corresponds to a specific energy value. Energy serves as the fundamental fuel for all activities in this world, and playing the game requires energy consumption. Energy exists off-chain and cannot be transferred.

The Energy value is determined based on this formula(l refers to levels).

$$
e = 30*l*(1+30%)^{l-1}+70
$$

The Energy value determines the maximum amount of Energy a user can regenerate every 8 hours. If the Energy is fully regenerated, it will not continue to increase.

| Level | Quality   | Energy |
| ----- | --------- | ------ |
| 1     | Common    | 100    |
| 2     | Rare      | 148    |
| 3     | Superior  | 222    |
| 4     | Epic      | 334    |
| 5     | Legendary | 498    |
| 6     | Supreme   | 738    |
| 7     | Mythic    | 1,084  |
| 8     | Ultimate  | 1,576  |
| 9     | Prime     | 2,272  |

If an account holds multiple Personas, both the energy cap and regeneration time will stack. If you hold up to 3 Personas, the regeneration efficiency will also stack. For example, if you own 3 Level 1 Personas, your Energy will fully regenerate to 100 \* 3 = 300 points within 8 hours. However, if you hold 4 or more Personas, the regeneration efficiency won’t stack, and the system will prioritize energy regeneration based on the highest-level Persona.

For instance, if A holds three Level 1 Personas (Energy value of 100) and one Level 2 Persona (Energy value of 148), the system will first regenerate 148 + 100 + 100 = 348 points within 8 hours, followed by an additional 100 points over the next 8 hours, after which the energy will stop increasing further.

Additionally, each account can link up to 9 Personas.