Black Deck

I downloaded Black Deck because the cover art promised a proper card-battling game, and the first few levels really are that pleasant. By chapter two the board gets much more crowded and the monsters even get reinforcements mid-battle, so my team of level-one cards started visibly running out of steam.

But what stopped me in my tracks wasn't the difficulty. I opened the upgrade screen, picked a card, and the figure 630 gold appeared. Then I looked down at the reward for the battle I had just won, which said exactly 22 gold.

Six cards on the table, one attack per turn

A battle takes place on two three-by-two trays, your team below and the monsters above, with up to six cards on each side. On your turn you tap one of your cards, then tap the enemy card you want to hit. The rest of your cards are immediately crossed out in red, a reminder that they're sitting this turn out.

The clever part is that both sides lose health in an attack, so choosing who hits whom is where the thinking happens. My 23-health knight card took out a 4-health rat, but dropped to 19 itself in the very same exchange.

On the far side of the board there's also a reinforcement slot with a countdown, and when it runs out a new monster joins the board whether you've cleared it or not. So battles always come with time pressure, and playing slowly isn't automatically playing safe.

The number on a card is both its health and its attack

Each card carries exactly one number. That number is both the health it has left and the damage it deals to the other side. A card that has taken a beating is therefore not only worse at absorbing hits but also hits much softer in later turns, a classic case of losing making you lose even more.

That makes focusing your attacks far more important than spreading them out, and I learned that lesson on the second level. I tried to split my attacks across three monsters at once, and the result was that I couldn't kill a single one before their reinforcements landed on the board.

A hero card stands in the middle and lifts the whole line

Of the six slots, one is reserved for a hero card. A hero doesn't hit much harder, but it boosts the teammates standing around it. My starting hero gave each melee teammate twelve percent extra starting strength. Mid-battle you'll see a few numbers on your side tick upwards while the other side keeps shrinking.

Each card also has its own attack type, melee or ranged, plus a targeting style and a few skill slots that open up as the card ranks up. The collection holds up to 700 unit cards and 280 hero cards, and you get ten deck slots to keep several different teams ready to go.

Three hundred levels, seven dungeons and a locked arena

Beyond the levels, the main map lays out a whole town. Each building is a mode, and most of them are locked by player rank. The arena opens at rank four, dungeons at rank five, guilds at rank six, and the wardrobe not until rank seventeen.

The campaign is split into chapters of seven levels each, the last one a boss, and the chapter's star milestones unlock extra rewards at 15, 29 and 43 stars. The publisher says the game has more than three hundred levels, seven dungeons and forty-eight bosses, so the stretch of map I had covered was only the warm-up.

One small detail I think is worth mentioning up front. The auto-battle button sits right at the top of the battle screen but only unlocks from chapter three, which means you tap every single turn yourself throughout chapters one and two.

New cards come from the summoning spot, which spends its own kind of ticket rather than gems directly. I did a ten-card hero summon and got eight four-star cards and two three-star cards. The guarantee milestones are spelled out on screen: fifteen summons guarantee a rarer card, and fifty-five guarantee a legendary one.

22 gold per level, and one upgrade costs 630

This is where the game starts making things hard, and it does it cleverly, because it never actually blocks your path. A campaign level costs four of your eighteen energy points, and a three-star win pays back 40 experience points, one summon ticket and 22 gold.

Meanwhile, taking an archer card from level one to level nineteen cost me three experience flasks plus 630 gold. In return, its attack jumped from 16 to 39. Do the maths and the gold alone equals nearly thirty levels, for just one of the six cards in a deck, and the level cap is all the way up at thirty.

The game does give some things away, but only in drips. You get one free unit card a day and one elite unit card a week, and next to the claim button there's a watch-an-ad button to cut the eight-hour wait. When I claimed the elite card, the wait timer jumped to nearly seven days.

The shop stands right next door with a much faster answer. The 15,000 gold pack, the 45,000 pack and the 100,000 pack are all sold for real money, and each one can be bought up to ten times a week. The biggest pack also throws in 1,000 gems and 18 energy.

Free Shop only works on game version 1.36.0

From game version 1.36.1 onwards, Free Shop no longer works. The game server now checks every transaction and requires real payment for every paid pack, so if you turn this option on and tap buy, the game shows an error and asks you to restart. If you're on a newer version, just keep this switch off. What follows is what I measured on version 1.36.0.

On that version, our mod removed exactly that obstacle. You open the game, tap the round red MOD button on the edge of the screen and flip the free pack switch. Then you go to the shop, pick any pack you like and tap its price button as usual.

I tried the 100,000 gold pack, and my wallet jumped from about 321,000 to 421,000. Gems went up by 1,000 and energy by 18, all within about a second. Google Play never opened, and the broken-payment message from before didn't show up either.

More importantly, that gold really spends. I used it to upgrade the archer card from earlier: the 630 gold was actually deducted, the card actually levelled up and its attack actually went up. After closing and reopening the game, everything was still there.

A few things to know up front so you don't expect the wrong thing:

• The weekly purchase limit of each shop item stays the same as in the original game; the mod doesn't loosen it.
• The special offers that pop up on the main screen, along with the subscription pack, can't be claimed yet.
• The slider right under the switch lets you claim several packs with one tap, up to ten.

Gorgeous, but nothing works without a connection

The visuals are the easiest thing to praise here: every card's artwork is sharp, and the effects when you flip new cards are really well done. Battles are short too, a minute or two per level, which suits anyone who grabs a few minutes and then puts the phone away.

The language menu offers eleven languages, and the whole interface, down to each card's skill names, is available in English. My one real complaint is how tightly the game is tied to its server.

I tried switching on airplane mode and reopening it, and it froze on the loading screen with nothing left but an offer to restart. So this isn't a game to take on a flight or anywhere with a weak signal.

On Google Play the game sits at 4.3 stars from 131,000 ratings and more than five million downloads. In other words it has a genuinely large player base, not some obscure name.

Who this game suits

If you like turn-based card battlers but dread games where you have to memorise a hundred rules, this is a gentle option. All the maths in a battle revolves around a single number on each card. The depth lies instead in building your team and raising your cards, and that's exactly where the game squeezes you for gold.

And if you played before and quit right when you realised every upgrade means dozens of levels of grinding, the mod above removed exactly what was blocking you, as long as you're on version 1.36.0. Your team grows strong in one evening instead of a week. The rest of the game, choosing who attacks whom across those six slots, stays exactly as the publisher wrote it.