From hopeful guesses to plain facts
Choosing how long to play this game means accepting that the bonus round may come early or late. Nobody can know in advance how often it lands, and the result of one session is random whatever the RTP. Two players with the same bet can finish a session far apart, so set a budget you can afford to lose before the first spin.
Checking the RTP version before you join is a choice worth making. The version running in the Casino Kings lobby is shown only in the game rules. Open those rules before you commit any money, so you know exactly which version you are playing.
Deciding whether the top prize should shape your bet means reading the maximum win as a limit, not a forecast. The maximum win of Mummy's Jewels 100 is x30,000 times the bet, and that ceiling is reached very rarely. Treat it as the most the game can pay, and keep your bet size in line with your budget.