Tesla's Invention Slot by Relax Gaming

The setting is a Victorian electrical workshop, all dark wood and brass fittings, with the 6x5 reel cabinet mounted like a piece of laboratory equipment between two arched windows. Glass coil tubes line the workbench, copper wiring snakes across the floor, and a chalkboard hangs in the corner. The reels themselves sit inside a brass-trimmed housing, and the four power-up meters run vertically down the left edge of the cabinet in colour-coded canisters: yellow for Win Spins, red for Additional Wilds, orange for Symbol Upgrade, purple for Multiplier.

Those meters are the whole reason to play this one. Every base spin can drop power-up symbols that charge those four canisters, and crucially the progress carries over between sessions at the same bet level. Walk away with three Wilds banked and a x3 Multiplier loaded, come back tomorrow, the meters are still where you left them. That changes how the base game feels - you're not just spinning for line wins on 15,625 ways, you're stockpiling for a payoff that hasn't happened yet.

The payoff is the Electric Dreams Win Spins feature, which triggers when one Scatter lands on reel 1 and one lands on reel 6 in the same spin. You start with a minimum of six spins plus whatever you banked in the yellow canister. Pre-placed Wilds from the red canister appear on the grid. The orange Symbol Upgrade swaps low pays out for highs at the start. The purple Multiplier applies to every single Win Spin for the duration. And here's the rule that makes it work: every Win Spin is a guaranteed winner. No dead spins. The feature continues as long as Coin or Power Pot symbols keep landing to maintain the "current" - three consecutive Re-Spins without one and the fuse blows, ending the run.

The Buy Feature sits at 88x your bet, an oddly specific number that probably nods to the voltage theming rather than rounding to a clean 80x or 100x. It buys a guaranteed Electric Dreams trigger at 96.64% RTP, slightly above base, and crucially it unleashes whatever you've already collected in the canisters - so a buy after a long power-up session hits very differently than one bought cold. Relax Gaming rarely builds slots that reward patient meter-grinding like this one does, and the persistent collection mechanic is the part most players will either love or find tedious depending on temperament.