Hero minting: how it works and why timing matters
The two-phase process, the 256-block window and why delaying the process step turns your hero into a Common.
Last updated: 2026-06-13Minting a hero in BombCrypto looks simple — you pay and get a hero — but under the hood there's a two-phase mechanism designed to prevent randomness manipulation. Understanding it is what separates players who lose good heroes from those who preserve their odds.
The cost of minting
Each mint consumes BCOIN (and, depending on the type, also SEN). The cost is set by the game's design contract and can vary by hero type (legacy or Hero S). Payment happens the moment you register the request.
The two phases
Phase 1 — Request
When you call mint, the contract charges the tokens and registers a request tied to a future target block (the current block plus a small offset). That target block serves as the random seed. No NFT is created yet — there's no hero, just a registered promise.
Phase 2 — Process
After the target block is mined, you call process. The contract reads that block's hash, uses it as the seed to roll rarity and stats, and finally creates the hero in your wallet.
Separating request from process prevents anyone from choosing the result: at the moment you pay, nobody yet knows what the future block's hash will be. This makes the draw fair and resistant to manipulation by miners.
The 256-block window — the critical point
Here's the part that catches many people off guard. The blockchain's virtual machine can only read a block's hash if it's within the last 256 blocks. Any block older than that returns zero. This is a technical limitation of the network, not a game choice.
If you wait beyond that 256-block window to process your request, the target block's hash is no longer accessible. When that happens, the contract enters a fallback path and forces Common rarity. The hero is still created — but as the worst possible tier.
| Scenario | Result if the window expires |
|---|---|
| Normal mint | Rarity forced to Common, with low stats. |
| Fusion | Total failure: the material heroes are burned and nothing is received. |
| Re-randomize abilities | Request abandoned; the cost paid is lost. |
256 blocks equal a few minutes on BSC. In practice you have a short window — on the order of minutes — between minting and processing. Past that, the hero becomes Common. This is exactly what makes the share of Commons on the network far higher than the theoretical draw chance.
How not to lose good heroes
- Process the mint immediately after confirming it. Don't let pending requests pile up in the wallet.
- If minting in batches, process each block before starting the next.
- Use a tool with auto-processing, like BombCrypto Analytics' Maestro, which calls process automatically a few seconds after the mint confirms.
Wallets with mint requests sitting idle for a long time are, in practice, guaranteed to be converting heroes into Commons. If you have old pending requests, process them as soon as possible — any chance of good rarity may already be gone, but there's no point letting it get worse.