ZapLab: Slot Overview

Players who haven’t looked through the related game docs may not know about the so-called “mad Dr Mayhem”, a 20th-century scientist whose questionable experiments aimed to use electricity to capture souls from the past. One outcome is Zappy, an electric lifeform with a personal grudge against the doctor who created him. Their clash plays out in ZapLab, a cluster pays online slot from Light & Wonder owned studio ELK Studios.

While Dr Mayhem’s work with power and souls sounds bizarre, the lab shown in-game appears fairly ordinary. Aside from a brain in a bubbling vat by the window, it looks like a proper place for scientific tinkering—though the eerie green glow under the floor hints that trouble is brewing. Filling the grid in the centre is a crowd of wide-eyed Reactoonz-style creatures, and, as is often true with an ELK Studios slot, the sound design pairs brilliantly with the visuals.

ZapLab is a cluster pays slot played on a 7×7 matrix. Winning clusters form when 5 or more matching pay symbols connect vertically and/or horizontally. Every symbol in a winning cluster is collected and removed (Zappy and feature symbols are not removed). The remaining symbols—excluding Zappy, Dr Mayhem, and feature symbols—then fall straight down, and new symbols drop in from above to fill the gaps. This avalanche process continues until no further cluster wins appear. To play, players can wager 20 c to $/€100 per spin or choose one of five modes from the X-iter feature buy menu – all have an RTP of 94%, and the math model is highly volatile (7/10).

Four eyeballed liquid bottles act as the lower-paying symbols, while 4 eyeballed monsters make up the high pays. Five-of-a-kind clusters pay 0.1x-0.5x, and clusters of 25+ are worth 20x to 1,000x. Four matching pay or wild symbols arranged in a square create a 2×2 symbol, and any empty positions beneath a big symbol are filled with 1×1 symbols of the same type. Wilds substitute for any regular pay symbol. Wins made up only of wilds pay the same as the top-paying symbol.

ZapLab: Slot Features

Alongside the avalanche mechanic, the game includes Monster features, feature symbols, Shockwaves, Zappy, and X-iter bonus buys.

Monster Meter

The Monster Meter tracks how many winning pay symbols have been collected. Once it is full, the Monster Meter grants either a random Monster modifier or a random feature symbol. Any modifier awarded by the Monster Meter is stored as pending until there are no more wins. The pending modifier then triggers, and the round continues until wins stop again before the next feature can activate. The possible Monster modifiers are:

• Monster Reload – awards a symbol redrop. Potential Zappy symbols remain during the redrop.
• Wild Flip – selects a random symbol and turns all instances of it into wild symbols.
• Monster Chunks – picks a random number of pay symbols or wilds and upgrades them into 2×2 symbols.
• Monstrous – chooses a random pay symbol or wild and expands it to 3×3, 4×4, or 5×5.
• Zapocalypse – a random number of Dr Mayhem symbols drop in and get zapped by Zappy.

Feature Symbols

Feature symbols may appear on any symbol drop or be granted by the Monster Meter. When feature symbols land as part of a symbol drop, they act as wild. Feature symbols trigger instantly when awarded from the Monster Meter, or otherwise they trigger when included in a winning cluster, activating after the refill.

• Omniblast – detonates and replaces regular pay symbols in an x-shape, including itself, with a randomly selected symbol. Feature symbols activate if struck by the beam. Wild, Zappy and Dr Mayhem are not affected.
• Electroshift – picks a random symbol type and upgrades every instance of it, including itself, into a higher-value symbol.
• Twilight Twirl – randomly chooses a payout symbol type, transforms itself into that type, and removes all other regular pay symbols.

Shockwaves

When the fifth Monster Meter is filled, Shockwaves begin, awarding all Monster modifiers in the following order – Monster Reload, Wild Flip, Monster Chunks, Monstrous, and Zapocalypse. If the Monster Meter fills again during Shockwaves, the sequence repeats.

Zappy

Zappy is wild, can land on any symbol drop, and substitutes for all paying symbols. If he’s part of a winning cluster, he jumps to a new random position, leaving a wild symbol behind. Zappy zap attacks Dr Mayhem symbols visible off the grid, increasing his multiplier. On the final zap attack before win evaluation, Zappy can expand to 2×2, 3×3, or 4×4. Dr Mayhem symbols are blocker symbols. When zapped off the grid, they increase the Monster Meter.

X-iter

The X-tier lets players jump into bonus modes, including Shockwaves Hunt, where each drop costs 3x the bet and has more than 3 times the chance of triggering Shockwaves, Zappy’s Turf, where each drop guarantees Zappy for 5x the bet, or Amplifier which has a pending feature from the Monster Meter and the Monster Meter only awards Monster features for 25x the bet. A game round guaranteeing Shockwaves costs 100x, while a Maxed Monsters drop with a Monstrous 5×5, and where the Monster Meter only awards Monster Chunks and Monstrous features until Shockwaves is triggered costs 500x the bet.

ZapLab: Slot Verdict

You could argue that ZapLab’s oddball story is paired with a game that isn’t quite as unusual, since it shares a number of similarities with Play’n GO’s Reactoonz series. From the staring, eyeballed cast to the way symbols are collected into a meter that then releases features at certain thresholds, it all feels very familiar—perhaps even a touch too familiar. Still, ELK Studios has chosen a highly entertaining formula: build the Monster Meter to unleash modifiers or feature symbols, and with enough luck, fill it five times consecutively to trigger Shockwaves. That’s unlikely to be simple to pull off, but if it happens, the payoff can be seriously exciting.

The real headliner in ZapLab is Zappy. Once he starts firing—most often seen during Maxed Monster buys—he becomes a blast. Bouncing around the grid, taking down the doctor, growing in size, stacking multiplier power: he’s part Jammin’ Jars, part his own unruly creature, and crucial to landing the strongest outcomes during testing. The top win recorded was bigger than what’s often seen in an ELK Studios demo, which is notable given there’s no dedicated bonus round, free spins, or respins—though results will naturally vary. Instead, it’s win after win, feature after feature, and Zappy-driven chaos, building to a 10,000x win cap.

It can take time before things really heat up (if they do at all), and buying the higher X-iter bonuses may require a hefty spend to force the action, but once Zaplab finds its rhythm it’s a well-crafted cluster pays, collect-to-trigger-features style slot. It may borrow heavily from Play’n GO’s ideas, yet setting the “inspiration” debate aside for a moment—and factoring in ELK Studios’ typically low RTP—Zaplab is still a solid pick for fans of the Reactoonz type of gameplay.