The minimum deposit at Rollbit is 0.00002 BTC (~$2). That figure is the cashier minimum, not the practical minimum. The practical minimum is the cashier minimum plus whatever the network fee is on the coin you send.
Rollbit supports 9 cryptos. The cheapest networks to deposit on, in our experience, are TRC-20 USDT, Litecoin, and Bitcoin Lightning where available. ERC-20 USDT and on-chain BTC will cost more in fees, sometimes enough to make a small test deposit not worth it.
If you are sizing a first deposit specifically to test Rollbit before committing real bankroll, $20 to $50 on a low-fee network is the practical floor. Anything smaller and the network fee starts to be a meaningful percentage of the deposit, which makes the test itself a bad bet.
The full payment-method breakdown, including which coins clear fastest at the cashier, is on the Rollbit payments page.
Score breakdown across seven categories, deposit-tested screenshots, payout times we actually measured, and the bits the operator does not mention in their welcome banner.
Read the Rollbit review