Crash at Roobet

What Roobet publishes about Crash

Roobet's help centre calls Crash "the crown jewel of Roobet": "the rocket goes up to a random multiplier each game and the goal is to cashout before it crashes" (Roobet House Games, 12 Nov 2026). It is a shared round, so every player sees the same rocket and the same crash point. Roobet's game page carries no RTP or house-edge figure for it (1 Nov 2026). The number has to be read from the verifier Roobet links on its fairness page, where the formula is published in full.

The formula in Roobet's verifier

The Crash verifier is a short program. Stripped to its steps:

hash = HMAC-SHA256(key = round's server seed, message = salt)
if hash is divisible by 25:   crash point = 1.00
otherwise:   h = first 13 hex characters of hash (52 bits),   e = 2⁵²
  crash point = floor( (100 × e − h) / (e − h) ) / 100

The code writes the divisor as parseInt(100 / 4), which is 25. A hash is divisible by 25 one time in 25, so 4% of rounds crash at 1.00x before the multiplier moves, and every bet in those rounds loses. In the other 96% the second formula applies. It reaches a multiplier t with probability 99 / (100t − 1), which is within a hair of the fair 1/t at low targets and 1% short of it at high ones. The house edge in Roobet's Crash is therefore four points from the instant-crash rule plus up to one more from the formula.

What that costs at each target

Putting the two steps together, a round reaches a target t with probability 0.96 × 99 / (100t − 1). The table sets that beside the same target in a game with a 1% edge, such as Stake's or Shuffle's Crash.

Arithmetic from the formula in Roobet’s Crash verifier, 12 Nov 2026. "Same target at a 1% edge" is 0.99 divided by the target.

The return runs from about 95.99% at the lowest target to 95.04% at very high ones: a house edge of roughly 4% to 5%, depending on where you cash out. At a 2x target it is 95.52%, so $100 wagered costs $4.48 on average against $1.00 at a 1% game. No target avoids it, because the 4% of rounds that end at 1.00x take the stake from every bet alike.

Seen the other way, the instant-crash rule means that out of 100 rounds about four are lost before any decision can be made. A 2x auto cash-out wins in about 47.8% of rounds, where a 1% game gives 49.5%. Those 1.7 points per round are the difference between the two prices.

The seeding event

Roobet's fairness page explains the two ingredients of the chain games. The server seeds: "We repeat this process until we have 2 million hashes -- 2 million server seeds. The very first game uses the 2 millionth server seed, and each game after that works backwards down the list of server seeds." The public value: "We commit to the hash of a crypto block before that block is mined, and we create all the server seed hashes before committing to this block. This ensures that we could not control the outcome of each game."

For the current Crash chain the commitment is a Pastebin post titled "Friday 18th of September 2026 10:43:42 PM CDT": "Crash seeding event! Our 2 millionth hash is 7a22a345e4a1cec94d80e49257dd71a8bea7c092a98ec19aff2d4d7233882dc6. The client seed will be the hash of the un-mined Ethereum block 26008955". The verifier's header repeats both values and gives the block hash used as salt, 0xd751043d3a3131fefe22d75a8ae1a7cb50b5b777992cf85b95260896062a5486.

Two points about this design. A chain of 2 million rounds is finite, so Roobet reseeds from time to time, and each new chain needs its own commitment; the one above is the chain in use on 12 Nov 2026. And the strength of the scheme rests on the commitment being public before the block existed. The date of a commitment is carried by the post itself, so anyone who wants to rely on a chain should note the commitment when it is made.

Verifying a round

1. Open a finished round in the game and copy its hash (the round's server seed).
2. On Roobet's fairness page choose Crash and press Verify Results. Paste the hash into the verifier.
3. The verifier prints the crash point for that hash and for the previous 100 rounds, each obtained by taking the SHA-256 of the one after it.
4. Compare the list with the game's history. Every match is a round whose seed was already fixed inside the chain.

Roobet's fairness page notes that "the current Client Seed can be viewed in the verification tool", which is the salt above. Our Crash verifier computes crash points for Stake and BC.Game, whose formulas differ from this one, and the Roobet seed checker covers the seed-commitment check for Roobet's seed-pair games. Neither reproduces a Roobet crash point; use Roobet's verifier for that. Background: what provably fair gambling proves and the general verifier.

Cash-out timing and Roobet's refund policy

The hash chain settles when the rocket stops. It does not settle whether your click arrived in time, and Roobet's help centre has an article on exactly that. "Crash is a game which solely relies on your connection to Roobet. The rounds are played out in real-time", and the listed causes of a failed cash-out are lag on your device or network, a click "close to the crash point" that arrives late, mobile instability, and a VPN or proxy degrading the connection.

The policy is stated without hedging. If the fault is on Roobet's side, "Roobet has an automatic refund system in place, if a site-wide or server sided issue affected the round, this results in the bet being automatically refunded". If it is on yours, "we are unable to refund for client-side connection issues due to this being out of our control". The recommended protection is the automatic cash-out: "It will automatically cash you out to the multiplier that you set, even in times of client-side latency issues."

That is good advice on its own terms. A target set before the round is executed by the server and cannot be late. It does not change the return, which is fixed by the table above.

Roobet Crash against Stake, Shuffle and Gamdom

Stake: BitcoinTalk seeding post (read 12 Nov 2026). Shuffle: help centre and game page, 12 Nov 2026. Gamdom: fairness page and sample code, 12 Nov 2026. Returns are arithmetic from each published formula.

Roobet's Crash is verifiable in the same way as the others and is the most expensive of the four to play, by a factor of more than four against Stake. It is also the only one of the four without a stated return, so the comparison is only visible to someone who reads the verifier.

Sources: Roobet fairness page and the Crash verifier it links (12 Nov 2026); Crash seeding post (18 Sep 2026); Roobet help centre, Roobet House Games and Crash Issues (12 Nov 2026); Roobet Crash game page (1 Nov 2026). Probabilities and returns are our arithmetic from the verifier’s formula.

The auto cash-out calculator shows hit rates for any target. Roobet's licence, KYC and withdrawal terms are in the Roobet review.

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