# LootBox System
The LootBox is a random box containing special rewards, which will appear as soon as users finish an activity. ([For Reference](https://medium.com/runblox/lootbox-is-finally-here-the-latest-exciting-feature-is-live-on-runblox-app-4b84a1e0dead))
### Opening Cost, Validity & Rewards
| Level | Images | Rarities of LootBox | Validity Period (hour) | Opening Cost (RUX) |
|---|
| 1 |  | Common | 24 | 10 |
| 2 |  | Rare | 36 | 20 |
| 3 |  | Epic | 48 | 50 |
| 4 |  | Hero | 60 | 100 |
| 5 |  | Legendary | 72 | 200 |
* **Validity period**
The page will prompt the user as long as the current LootBox is still valid for the remaining valid time.
The LootBox should be opened before its expiry time.
If the user fails to open the LootBox before the expiry time, the LootBox will automatically be discarded.
* **Opening cost**
To open a LootBox, you will need to pay a certain amount of RUX as an opening fee.
* **Rewards**
There will be a 50% chance of getting either 1% RUX or double the opening cost of each LootBox.
### Description of the LootBox drop rate and rarity
#### Step 1. Calculation of drop rate
| Parameters | Proportion | Value Range |
|---|
| Energy Consumption | Low | ≥ 1 |
| Shoe Luck | High | ≥ 0 |
**Formula**
*L = Arctangent function control parameter*
*A = The weighted average of energy consumption value and the shoe Luck attribute value*
*Do= Upper limit of dropping rate*
*D = Drop index*
#### Step 2. The Rarity of the LootBox
The Rarity is determined by the LUCK score.
As the value of LUCK increases, so does the rarity of the LootBox and the score.
There will be 10 different ranges of LUCK scores.
### LootBox activity
For future activities, we will add even more prizes to high-quality boxes.