Native Randomness Sourcing with Looser Guarantees

Asphodel's Prologue, a fully onchain game on Ethereum, sources randomness for its Taruchi mint and training systems from RANDAO values of future blocks, verified via RLP headers against EIP-2935's historical blockhash contract to extend the read window to 8191 blocks (~27h) at ~15k gas overhead. The authors deliberately break EIP-4399's recommended 4-epoch lookahead (~25min) to preserve 1-2 block UX, arguing the cost of withholding bias (~50mETH per bit, halved on average) exceeds the value of equivalent rerolls priced at 3 ONYX (~3.69mETH), with an attacker needing 7+ consecutive proposer slots to profit. They acknowledge caveats from recent RANDAO manipulation research (selfish mixing, target slot attacks) and note that even large stakers like Binance (~9.3%), Coinbase (~7.3%), and Figment (~4.1%) would need years on average to land such streaks, with concentrated block-production gaps making any attack detectable.