Mega Jackpot
How it works
Draw Mechanics
- Frequency: Runs EVERY DAY at 00:00 UTC
- Win Chance: 2% chance each day to select a winner
- Rollover: 98% chance jackpot rolls over to next draw
- Average: 1 winner every ~50 days
- Prize: When winner selected, takes 100% of accumulated pool
Winner Selection Process
🎲 Step-by-step algorithm:
Step 1: Chainlink VRF Request
System requests a random number from Chainlink VRF (verified random function)
Step 2: 2% Probability Check
Contract checks: randomWord % 50 == 0
If random number divides by 50 evenly → proceed to winner selection. Otherwise → jackpot rolls over.
Step 3: Random NFT Selection
If 2% hit, system randomly picks one NFT from all minted NFTs (using totalSupply)
Step 4: Eligibility Validation
Selected NFT must meet 2 requirements:
- NFT must exist (have an owner) — if burned, the winner is reselected by VRF
- NFT must be within valid Mega Draw range:
megaDrawStart ≤ currentDraw ≤ megaDrawEnd
Step 5: Retry Logic (Rejection Sampling)
If selected NFT is invalid, system tries again till a new existing NFT is found (up to 64 attempts)
Uses rejection sampling method: generate → validate → accept or retry
Result:
✅ Valid NFT found → Winner gets 100% of jackpot
❌ No valid NFT found → Jackpot rolls over
Mathematical Example
Scenario: Day 45 Draw
- Current Pool: 1,500 TWT accumulated
- Total NFTs Minted: 8,000 NFTs
- Chainlink VRF returns: randomWord =
123,450 - Check 2%:
123,450 % 50 = 0✅ (proceeds to selection) - Random Index:
hash(123450, 0) % 8000 = 3,247 - Selected NFT: Token ID #3247
- Validation: NFT #3247 is Legendary (70 days participation), minted on Day 1
- megaDrawStart = 1, megaDrawEnd = 70
- Current draw = 45 →
1 ≤ 45 ≤ 70✅
- Winner: NFT #3247 wins 1,500 TWT (100% of pool)
Counter-example: Rollover
- Chainlink VRF returns: randomWord =
123,451 - Check 2%:
123,451 % 50 = 1❌ (not divisible) - Result: No winner, jackpot carries over to Day 46 with additional mints
Pool Accumulation
The Mega Jackpot receives 20% of all mint fees:
- Every 1 TWT from Letter NFT minting → 0.20 TWT goes to Mega Jackpot
- Pool accumulates until a winner is selected
- No maximum cap - pool grows until won
Participation Timeline
Your Letter NFT's participation period depends on its rarity and TWT staking badge:
Participation Days Calculation
Base participation:
- Standard: 30 days
- Rare: 50 days
- Legendary: 70 days
Staking bonuses:
- Silver Badge (50+ TWT staked): +10 days
- Gold Badge (250+ TWT staked): +20 days
Standard + No Badge:
30 = 30 days
Standard + TWT Staker Silver Badge:
30 + 10 = 40 days
Standard + TWT Staker Gold Badge:
30 + 20 = 50 days
Rare + No Badge:
50 = 50 days
Rare + TWT Staker Silver Badge:
50 + 10 = 60 days
Rare + TWT Staker Gold Badge:
50 + 20 = 70 days
Legendary + No Badge:
70 = 70 days
Legendary + TWT Staker Silver Badge:
70 + 10 = 80 days
Legendary + TWT Staker Gold Badge:
70 + 20 = 90 days
Important:
Staking badge is determined at mint time and remains static forever. Staking TWT after minting will not change your existing NFT's participation period. To benefit from staking bonuses, stake TWT before minting.
Understanding Your NFT's Eligibility
Each Letter NFT shows its Mega Draw eligibility range:
Example: "Valid # 6--65"
- Means you can participate in Mega Draws #6, #7, #8, ..., #65
- Total: 60 draws (if Standard NFT)
- Or 60 draws (if Rare NFT)
- Or 60+ draws (if Legendary NFT with bonuses)
Checking Results
After the draw is finished, you can check results:
- App Page: Visit app.letterfi.xyz to see the latest draw results
- User Cabinet: Navigate to the Mega Draw section in your User Cabinet
Strategy Tips
Maximize Participation
- Mint Legendary NFTs: Longer participation period (70 days)
- Stake TWT: Get Gold Badge for +20 days bonus
- Multiple NFTs: Each NFT is a separate entry
Timing Considerations
- Early mints: More draws to participate in
- Staking early: Lock in bonus days from the start
- Hold long-term: Let your NFTs accumulate more draws
Fairness
Chainlink VRF
All draws use cryptographically secure randomness
On-chain Verification
Every draw result is publicly verifiable
No Manipulation
Impossible to predict or influence outcomes
Transparent
Pool size and winner selection visible on-chain