ERC-20 is the Ethereum network's token standard. Every token moving on that chain — USDT, USDC, LINK and thousands of others — follows the same rulebook, which is why every wallet and every exchange can handle them the same way.
What that means at a casino
In a casino cashier ERC-20 is usually one network option among several. The address starts with 0x and the transaction confirms in minutes. The fee is always paid in ETH, not in the token being sent — meaning that to send USDT you also have to hold a little ethereum in the wallet. Without it the transfer does not happen, even if the USDT balance is there.
The fee fluctuates, and considerably
The price of an ERC-20 transfer depends on the gas fee, which is set at auction. The same transfer can cost under a euro in the morning and ten at peak time. With small and frequent deposits that eats a significant share of the money — by comparison, the same transfer on TRC-20 usually costs under a euro every time.
The costliest mistake
A BEP-20 address also starts with 0x. Those are different chains, and getting back money sent to the wrong network depends entirely on the casino's goodwill — most do not return it. Always choose the network in the cashier first and only then copy the address. The difference is explained in the post TRC-20 vs ERC-20.
When to choose ERC-20
When your money is already in an Ethereum wallet and gas happens to be low. If you are starting from scratch, TRC-20 is cheaper for a stablecoin. The houses that accept ETH are collected in the Ethereum casino list.