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Dice

Chance and Multiplier

Dice is a game where you roll over (or equal to) or under (or equal to) a number to win. Chance is chosen by the player (0.01%-98%). The multiplier is set so the return is always 0.99 compared to the win chance. Through a simple formula (with Chance ranging from 0.1 to 95) the multiplier for every chance input from the player can be calculated.
Multiplier=0.99100Chance\text{Multiplier} = 0.99 \frac{100}{\text{Chance}}
The available multipliers can be found in the Dice contract where 10421 stands for the 1.0421x multiplier and 9900000 for the 990x multiplier:
if (!(multiplier >= 10421 && multiplier <= 9900000))
Here are some examples of specific outcomes:
Player outcome
Chance
Multiplier
Win
95% (highest)
1.0421x
Win
50%
1.98x
Win
49.5%
2x
Win
0.1% (lowest)
990x
Loss
0.1%-95%
0x

House Edge

The 1% house edge is taken when the win chance is being calculated, because 99000000000 is always being divided by the multiplier:
uint256 winChance = 99000000000 / game.multiplier;
When we take the 2x multiplier as an example, 99000000000/20000=4950000 leads to a 49.5% win chance. This is a 1% house edge (50.5-49.5). On a win or loss the average return is always 0.99.

Odds

The numbers above lead to the following odds for Dice:
Odds
Outcome
Decimal odds
0.99
Return to Player
99%
Probability odds
49.5%