Oil Boom

Oil Boom is a mining-themed slot from Lucky Devil with an RTP of 96.7%, high volatility and a maximum win of 25,000x. The game uses a 6-reel, 5-row cluster pays format, where matching eight or more symbols anywhere on the grid trigger a Clear & Cascade mechanic that removes winning symbols and drops new ones into their place.

Prize barrels fall into an Oil Vat during cascades, building pressure tracked by eight lamps across the reels. Each barrel lights one pressure lamp, while each subsequent drop lights two lamps. When all eight lamps are lit, the vat bursts and doubles every prize stored inside. The vat collects prizes and multipliers throughout the spin, which are awarded at spin end in the base game. A Collect action empties the vat for its doubled value.

Two bonus symbols activate special effects during cascades. Pipe Flush clears all symbols in a target row, while Pressure Burst clears symbols in a 3x3 area. Special symbols remain on the board after these clears, and any cascade wins completed after a clear still count.

Four or more Bonus symbols anywhere on the grid trigger Free Spins. Each additional Bonus symbol beyond the initial four awards one extra free spin. The Oil Vat, multiplier and pressure level all carry into the Free Spins round, where pressure continues to build across spins. After the final free spin, a Collect action empties the vat.

Five bonus buy options are available. Ante Bet costs 2x your bet, Gusher Spin costs 100x, Free Spins costs 200x, Mystery Free Spins costs 250x and Super Free Spins costs 400x.