This hash was generated before the round started. After the casket opens, the server seed is revealed so you can verify the result was predetermined.
Check Game Seed
Verify any past round using the server seed (revealed after the casket opens) and round number.
Algorithm (HMAC-SHA512)
const crypto = require('crypto');
function seededRoll(serverSeed, clientSeed, round) {
const data = clientSeed + '-' + String(round);
const hmac = crypto.createHmac('sha512', serverSeed);
hmac.update(data);
const hash = hmac.digest('hex');
const num = parseInt(hash.slice(0, 8), 16);
return num % 128; // weighted against drop table
}
Caskets — Rules
How It Works
1A casket is opened and a single item is revealed. The outcome is determined by the official OSRS drop table with real drop rates.
2Enter your bet amount, then click on a category (Coins, Gems, or Rare) or a specific item to add that amount to it. You can spread bets across multiple options, then click Confirm Bets to lock them in.
3Once the first bet is placed, a 5-second countdown begins. Each additional bet adds 1 second (max 10s) so others can join in.
4This is a global game — everyone bets on the same casket opening. Multiple players can pile in on the same round.
5All bets are in OSRS Mill (M). You can type amounts as K, M, or B — they all convert to Mill. Example: 500K = 0.5M, 1B = 1000M.
6You can place up to 3 bets per round. Min bet: 1M. Max bet: 5B on Coins/Gems, 3B on Rare, 1B on specific items.
Category Payouts
Category
Chance
Payout
Max Bet
Coins
46.9%
2x
5B
Gems
45.3%
2x
5B
Rare
7.8%
10x
3B
Specific Item Payouts
Item
Chance
Payout
Max Bet
Uncut Sapphire
25%
3x
1B
Uncut Emerald
12.5%
5x
1B
Uncut Ruby
6.25%
12x
1B
Uncut Diamond
1.56%
30x
1B
Cosmic Talisman
6.25%
12x
1B
Loop Half of Key
0.78%
30x
1B
Tooth Half of Key
0.78%
30x
1B
Minimum bet across all options: 1M
Drop Table
All drop rates are based on the official OSRS Casket drop table (128 total weight) as documented on the Old School RuneScape Wiki.
Provably Fair
The casket outcome is determined by a provably fair HMAC-SHA512 system using the official OSRS Casket drop table (128 total weight). A public hash of the server seed is shown before each round. After the casket is opened, the server seed and client seed are revealed for verification.
0M
Gems
Rare
Uncut Emerald
Uncut Ruby
Uncut Diamond
Loop Half of Key
Tooth Half of Key