Das xBoot: Slot Overview

Das Boot is a movie released in 1981, which received a glowing critical response and is viewed by many as one of the greatest and most expensive films Germany has ever produced. It was based on a book of the same name published in 1973 by Lothar-Günther Buchheim, describing his experiences aboard German sub U-96, in the hazardous waters of the Atlantic Ocean during World War 2. U-boats sinking Allied ships during WW2 might not be the first topic that springs to mind when developers brainstorm new ideas. If there is one thing Nolimit City has taught us, it's they are no regular studio, taking Das Boot, and transforming it into Das xBoot, a complex slot jam-packed with an arsenal of extras.

Das xBoot is a real amalgamation of features and mechanics from previous Nolimit slots all rolled into one. The graphics and effects are full-on Das Boot, the action located in a murky grey sea next to the sub's starboard side. Paradoxically, since Das xBoot is based on the Kriegsmarine, it feels a little tame, coming so soon after Mental. However, it packs in plenty of atmosphere, with come book style looks offset by a brilliant Jaws meets Klaus Doldinger meets Blade Runner 2049 soundtrack, which adds a layer of lurking menace to induce an enjoyable tense feel.

Playable from 20 p/c to $/€100 per spin, the base game is played on a 6-reel panel arranged in a 2-3-4-4-3-2 formation, which chops and changes depending on the game phase or if certain symbols are present. In its most basic form, there are 576 ways to win, though this can balloon to 75,712 under the right conditions. It kind of goes without saying that Das xBoot is a highly volatile slot, rated 10 out of 10 by its maker. RTP is variable, so be on the lookout for the 96.03% version as it is the most generous one. Wins occur at a frequency of 22.07%, while free spins trigger every 211 spins on average - there are two bonus round levels, depending on how many scatter symbols hit to activate them.

Diving down further to the symbols, we come across ten of them as the regular pays, plus various special symbols. On the low pay side are 10-A card ranks, then five crew members as the premiums – chefs, radio guys, engineers, periscope operators, and captains. The most valuable is the Kapitanleutnant, worth 20 times the stake for a six of a kind winning combination.

Das xBoot: Slot Features

Going to sea for any length of time requires plenty of stores to tie you over, and Das xBoot comes with loads of extras such as xNudge Wilds, xWays, xBomb Wild Multipliers, Silent Hunter Spins, and Wolf Pack Spins.

Starting with the wilds, the xNudge Wild is a 4-row high wild symbol that always nudges to be fully visible. Each nudge increases its wild multiplier by +1. xNudge Wilds land on reel 3 or 4 only, except in Silent Hunter Free Spins, where it only lands on reel 4. All multipliers add to each other, and wins are evaluated using the total multiplier.

The xWays symbol lands only on reels 2 or 5 to reveal 2-3 instances of a regular random symbol. If more than one xWays symbol lands on the reels, they all reveal the same pay symbol.

When an xBomb Wild lands, the global win multiplier increases by +1, then it explodes, removing all non-winning symbols from the reels. Exploded xBombs convert to wild symbols after exploding. The remaining symbols after the explosion drop to the bottom of the grid, and new ones tumble in. If free spins trigger on the same spin, the win multiplier is carried over to them.

Keep an eye out for the sonar display, it's the scatter symbol, appearing on reels 2-5. Landing 3 of them triggers 8 Silent Hunter Free Spins, or 4 of them in view activates 8 Wolf Pack Free Spins.

For Silent Hunter Free Spins, reel 3 grows to 8 positions high (like a periscope), and a new Periscope Wild may land on it. If matching symbols land on reels 1 and 2, with a Periscope Wild on reel 3, a torpedo launch sequence occurs, and the win multiplier increases by +1. This is a short boat attack animation, and if the boat is sunk, the Periscope Wild covers reel 3. Also, for each position, the stack of Periscope Wilds nudge down to cover the reel, the multiplier for that reel increases by 1. This value is added to any global win multiplier. If the attack misses, the Periscope Wild remains a single wild. Finally, any scatter in view adds +2 additional free spins.

For Wolf Pack Free Spins, a torpedo tube appears beneath reels 2-5. When new torpedo wild symbols hit on these reels, they drop an xWays symbol onto the torpedo area. These xWays symbols start on x2, increasing by +1 for each following torpedo wilds that hit from then on, up to a maximum of x9. When all 4 positions of the torpedo are filled, it launches out of the way to reveal xWays symbols. On reels 2 or 5, these revealed xWays transform into the respective number of regular symbols; on reels 3 or 4 they become the applicable number of wild symbols. A torpedo launch also increases the win multiplier by +1. Like before, scatter symbols award an extra +2 free spins.

The last feature is the Nolimit Bonus feature buy option where players can buy either bonus game. Silent Hunter Free Spins cost 75x the bet possessing an RTP of 96.57%, while Wolf Pack Spins cost 350x the bet while having an RTP value of 96.58%.

Das xBoot: Slot Verdict

Das xBoot has a higher than usual complexity, though it's nowhere near as confusing as the previous game Mental was. It will probably take a few bonus rounds to completely clock what is going on, yet there is no residual confusion left once everything falls into place. It's funny, after Mental, Das xBoot feels rather light by comparison, which is an odd thing to say about a slot based on one of the most dangerous battlegrounds of World War 2. Comic book graphics soften the theme to an extent, but sinking enemy ships and the menacing soundtrack do a great job of building tension.

The features are a who's who line up of Nolimit City classics. Limiting special symbols to certain reels was a good idea, adding variety while also amplifying each other's effects should they trigger in unison. Silent Hunter Free Spins would usually produce 1 or 2 Periscope Wilds per round, giving you the chance of filling reel 3 with wilds. Get an xWays symbol or xNudge in there at the same time, and results can be exciting. Das xBoot is a volatile slot, though, so brace for plenty of 'Scheisse' moments, too (the game's word here).

As we've seen in previous Nolimit City games, all it takes is one stunning spin to change everything, and Wolf Pack Free Spins are where this is most likely to happen. Here is where you want to build as high a collection of xWays symbols on the torpedo as possible. Then, if you manage to launch the torpedo, the following spin can be absolutely crazy with all those potential wilds, multipliers and additional ways in play. Prepare for some major teasing, however. One time during testing, the very last Wolf Pack spin launched the torpedo, jacking ways, alongside wild stacks, xWays, the whole works… with absolutely nothing connecting on the first reel. That produced a humorous yet frustrating 'Nein, nein, nein' animation as the game tried to commiserate with the close but no cigar outcome.

Das xBoot's gameplay is so all or nothing it's like a metaphor for a fruitless or successful submarine hunt. On a darker note, some estimates put the chances of U-boat sailors surviving the war at 20%. By comparison, the odds of hitting Das xBoot's max win are even slimmer. However, do so, and a colossal haul worth 55,200x the bet is coming your way, triggering the Das Gold Des Roter Teufel feature as the round shuts down.

Having memories, or nightmares, of Mental fresh in your mind may diminish Das xBoot's impact, but this doesn't stop it from being another big, volatile juggernaut from Nolimit City. Once again, the team has picked a theme most others would shy away from and stacked it with the sort of gameplay that has no qualms torpedoing starry-eyed players out of the water as much as reward them.