Coinroll.it - Dice rolling game | Instant bets | Off-the-chain | 1% House edge

[Scrat Acorns]

Coinroll is a new dice rolling game with a few interesting features:

A house edge of only 1%

Unconfirmed deposits
We accept unconfirmed transactions. You can begin playing instantly - no registration is required.

Deferred withdrawals
You can choose to have your winnings sent to an address once your deposit has cleared. Staying on the website while your transaction is queued is not necessary.

Instant bets
Bets are off-the-chain and are processed instantly while still being provably fair. As such, you can bet as low as 0.00001 BTC.

API
An easy-to-use interface is available for those who would like to use Coinroll from the command line or integrate it into their projects.

Custom games
While a few preset games are available, you can set a target number from 1 to 64000 and your win odds and multiplier will be calculated accordingly.

Here's an example of a bet. More information on provability and database dumps are available here.

Betting limits will slowly be increased over the coming weeks.

Come check it out at https://coinroll.it

[1713906046]

1713906046

[1713906046]

1713906046

[1713906046]

1713906046

[1713906046]

1713906046

[danieldaniel]

Game is really cool.  I lost .01 BTC

[Namworld]

So pros:
- 1% house edge
- Unlimited instant bets after a deposit
- Fees only once per withdrawal
- No blockchain spam on each bet
- Still provably fair with pre-disclosed hash of the secret used for the day, with actual secret key disclosed daily.
- API, in case someone wants to automate betting. Kinda boring not betting yourself tho, IMO.

Cons:
- Got to remember an account key or withdraw before leaving. At least balance remains recoverable if you can sign with one of your deposit address, in case the key is lost. Edit: Or not delete cookies before withdrawing.

Looking good.

[Scrat Acorns]

Cons:
- Got to remember an account key or withdraw before leaving. At least balance remains recoverable if you can sign with one of your deposit address, in case the key is lost.

Cookies are set to expire in 10 years, assuming you don't delete them or visit the website in Incognito mode.

[BRules]

Unconfirmed deposits
We accept unconfirmed transactions. You can begin playing instantly - no registration is required.

For now it won't be a problem, but let's assume that you maximum bet go as high as satoshi dice, so you may review this functionality because the double spends:

- sent 500 btc with no fee
- played and lost
- double spend with a generous fee


I also saw that every time I refresh the page, a new deposit address is showed to me. so, are all the address showed exclusively mine or they are just temporary address? if they are temporary, you should say for how long they will be assigned to my account.

[dooglus]

I opened the 'details' of my account (username and password) and selected the text to copy it somewhere safe.  The copied text comes out like this when I pasted it:

Code:

Account details

Your balance will be available next time you visit this website by means of a cookie.
If you would like to use your balance on another computer you may login at https://coinroll.it/login using the following credentials:
User ID8277-db77-0062PasswordARIUm9Eyt1fGNL

The user id and the password are all run in to each other as you can see.  Maybe put some spaces or something in there?

Edit: the same issue happens if I copy/paste the bet history:

Code:

36802< 64238fa870f1e518e#0Apr 30 2013 - 05:410.001 BTC0.00101

There must be some way of making copy/paste work better even though you're not using HTML tables.

Edit: also, there's no feedback if the number I type into the 'select game' form is too big.  I'd like it to tell me what the maximum number is at that point, rather than having to switch back to the FAQ or wherever I saw it before.

Edit: Custom games <64175 through <64238 all pay out the exact same multiplier (1.01x).  You should probably use more decimal places for the high-probability low-multiplier games so that the payouts are more fair.  The <64175 game pays out just 1.01x, that's a 1.097% house edge, almost 10% higher than the claimed 1%.  It looks like you're rounding the multiplier down, so the house edge goes higher than 1%, further in the house's favour:

In this example I was paid
  0.0001 0100
when a true 1% edge game would have paid 0.99 * 65536/64175 * 0.0001 =
  0.0001 0109 (9555)

ie. the 100 satoshis I won 'should' have been 109 or 110 satoshis (10% more):


Note that it isn't just the high-probability, low-payout games that have this issue.  <21620 through <21626 all pay out exactly 3x.

Also, it would be good to see the payout multiplier in the table of previous games played.

The 'withdraw' popup doesn't have a 'cancel' button or an 'x' in the corner to close it, and escape doesn't get rid of it either.  Clicking 'withdraw' again got rid of it, but that's a little less than obvious.

Other than all that (all of which is really minor) I like how the game works.  

[Scrat Acorns]

For now it won't be a problem, but let's assume that you maximum bet go as high as satoshi dice, so you may review this functionality because the double spends:

- sent 500 btc with no fee
- played and lost
- double spend with a generous fee

Edit: This can be (mostly) avoided.

I also saw that every time I refresh the page, a new deposit address is showed to me. so, are all the address showed exclusively mine or they are just temporary address? if they are temporary, you should say for how long they will be assigned to my account.

They are yours. They are assigned to your account forever.

[Zaih]

Your missing the point on the double spending. If they win they won't double spend, if they lose they will.

[Scrat Acorns]

The user id and the password are all run in to each other as you can see.  Maybe put some spaces or something in there?

This what user-select: none supposedly does but Chrome and Firefox throw a hissy fit if you enable it. I will try floating the userid and password or add some spaces on top of the margin.

Edit: also, there's no feedback if the number I type into the 'select game' form is too big.  I'd like it to tell me what the maximum number is at that point, rather than having to switch back to the FAQ or wherever I saw it before.

I will add some sort of feedback.

Edit: Custom games <64175 through <64238 all pay out the exact same multiplier (1.01x).  You should probably use more decimal places for the high-probability low-multiplier games so that the payouts are more fair.  The <64175 game pays out just 1.01x, that's a 1.097% house edge, almost 10% higher than the claimed 1%.  It looks like you're rounding the multiplier down, so the house edge goes higher than 1%, further in the house's favour:

To make things simpler and reduce the decimal digit spam, multipliers are rounded down to 4 significant digits. This makes the effective house edge float between 1% - 1.1% depending on the number. I still think that an 0.05% (on average) difference is insignificant compared to the advertised 1% house edge. Maybe I should add this to the FAQ.

ie. the 100 satoshis I won 'should' have been 109 or 110 satoshis (10% more):

You actually won 10100 satoshis. If you define "won" as the delta between bet and return, then a < 65500 game (not allowed, but just for the sake of argument) would always be in the negative, multiplier rounding or not. Maybe I should have the maximum number set to 60000.

The 'withdraw' popup doesn't have a 'cancel' button or an 'x' in the corner to close it, and escape doesn't get rid of it either.  Clicking 'withdraw' again got rid of it, but that's a little less than obvious.

All popups close if you click outside them. I will make it so that esc works as well.

Other than all that (all of which is really minor) I like how the game works.

Thanks!

[Scrat Acorns]

Your missing the point on the double spending. If they win they won't double spend, if they lose they will.

There is a system in place to combat that scenario. Obviously I can't go into specifics.

[BRules]

I also saw that every time I refresh the page, a new deposit address is showed to me. so, are all the address showed exclusively mine or they are just temporary address? if they are temporary, you should say for how long they will be assigned to my account.

They are yours. They are assigned to your account forever.

so I must ask, which bitcoin client you're using to run your system?

Your missing the point on the double spending. If they win they won't double spend, if they lose they will.

There is a system in place to combat that scenario. Obviously I can't go into specifics.

I have my doubts about that.

unless I'm missing something, the only way you can track a bad user is through their IP, cookies or bitcoin address.

A bad user will use TOR or Web Proxys to avoid the IP tracking, use the browser in incognito mode to avoid cookie tracking, and they can generate as many bitcoin address as they want and use mtgox to unlink his addresses.

maybe you should take a look on this thread:
[SUCCESS] Double Spend against a satoshidice loss

[Scrat Acorns]

maybe you should take a look on this thread:
[SUCCESS] Double Spend against a satoshidice loss

Maybe aforementioned system was inspired by that thread.

[BRules]

so, kudos for you if your system will really avoid this problem.

And about your bitcoin client? I'm only asking because I have heard that the original client will become very slow if there are thousands of bitcoin addresses in your wallet.

[Scrat Acorns]

And about your bitcoin client? I'm only asking because I have heard that the original client will become very slow if there are thousands of bitcoin addresses in your wallet.

Custom software.


FAQ has been updated. There were also some minor UI improvements.

[bluepoodle]

I love this site. Fun and easy.

[🏰 TradeFortress 🏰]

Neat user interface. Higher max bets please.

[Scrat Acorns]

5 Bitcoins are up for grabs.

More details.

[iANDROID]

Bet "§" and all your balance is GONE!

[Scrat Acorns]

Bet "§" and all your balance is GONE!

Not gone, it's some sort of weird rounding/display error. In the process of fixing it.

EDIT: Fixed, sorry for the delay. Press F5 to reload the client side javascript.

[iANDROID]

Bet "§" and all your balance is GONE!

Not gone, it's some sort of weird rounding/display error. In the process of fixing it.

EDIT: Fixed, sorry for the delay. Press F5 to reload the client side javascript.

No problem  .

To which URL is it possible to use your API?(I may have not seen it)