Chance Based Rarities

One of Crystara's most powerful features is the ability to create detailed rarity tiers with precise probability distributions for your NFT collections, fully on-chain.

Understanding Rarity Tiers

Rarity tiers allow creators to organize their NFTs into groups with different levels of scarcity. On Crystara, you have complete flexibility to:

• Create any number of rarity tiers (Common, Rare, Epic, Legendary, etc.)
• Set exact probability percentages for each tier
• Assign different traits, attributes, or utilities to different tiers

Setting Up Rarity Tiers

When creating a Gacha Collection, you'll be able to define your rarity structure:

1. Define Tiers - Create named tiers (e.g., Common, Uncommon, Rare, Ultra Rare)
2. Set Probabilities - Assign percentage chances to each tier (must total 100%)
3. Assign NFTs - Upload or create the NFTs that belong to each tier
4. Configure Metadata - Add rarity information to the NFT metadata

Example Rarity Structure

Here's an example of how you might structure a 1,000 NFT collection:

Rarity Tier	Probability	Number of NFTs	Description
Common	50%	500	Basic items with standard attributes
Uncommon	30%	300	Enhanced items with improved attributes
Rare	15%	150	Special items with unique attributes
Legendary	4%	40	Powerful items with exclusive attributes
Mythic	1%	10	One-of-a-kind items with exceptional attributes

Verifiable Fairness

All rarity distributions on Crystara are powered by Supra's decentralized Verifiable Random Function (dVRF), ensuring:

• Transparency - The randomness process is fully verifiable on-chain
• Fairness - No one, not even Crystara, can manipulate which NFTs are assigned
• Security - The random number generation is cryptographically secure

Best Practices

• Balance Your Tiers - Too many ultra-rare NFTs can devalue your collection, while too few can frustrate collectors
• Communicate Clearly - Make your rarity structure transparent to collectors before they mint
• Consider Utility - Different rarity tiers can offer different levels of utility or benefits
• Test Your Distribution - Use our simulation tools to visualize how your collection might distribute

Advanced Features

• Nested Rarities - Create sub-rarities within tiers for even more collection depth
• Trait-Based Rarities - Define rarities based on combinations of traits
• Dynamic Adjustments - Adjust probabilities based on minting progress (requires advanced setup)

For step-by-step instructions on implementing your rarity structure, see our NFT Launch Pad documentation.