Your quick-reference guide to optimal strategies, profitability and terminology in Roblox COS.
The recommended progression is:
Bankroll is the amount of $ you should have before opening a case if you want at least a given chance of avoiding bankruptcy. It is calculated from the case's variance and cost.
Confidence is that target probability. For example, at 95 % confidence the suggested bankroll is big enough that, statistically, you will survive 95 % of possible unlucky streaks.