Lucky Defense!

The second screenshot on the US App Store page for Lucky Defense! shows a gold banner that reads "Legendary Tier Summon! 0.01% Chance!" Below it, in large brushstroke letters, is the tagline "LUCK IS FAIR!"[1] It is a good summary of the pitch. It also sets up the most awkward chapter in the game's recent history.

Lucky Defense! is made by 111 Percent, a Seoul studio. On September 27, 2026, it sits third on Apple's top-grossing games chart in South Korea and 49th on the free chart[2]. In Taiwan, where it is sold as 運氣拚輸贏, it is 38th on the grossing chart. On the same day it does not appear in the top 100 games by revenue or downloads in the United States or Japan[2]. Everything below was checked on that date against the App Store, Google Play, 111 Percent's odds page and the official Korean fan cafe.

Two fields, one monster lane, two players

The store screenshots explain the board faster than any description[1]. Two rectangles of grass are stacked on the screen, one for each player. Monsters walk a dirt loop that wraps around both. At the top sit the wave number, a timer, and a skull icon next to a counter such as "11 / 100."

What you do is summarized in Google Play's English description: summoning units is based on luck, it is a tower defense game, you can merge units without knowing what you will get, and if you feel lucky you can "take a big swing with the roulette"[3]. The first release on Google Play is dated May 23, 2024[3]. Apple's store record lists May 26 of the same year[4].

After a boss, a reward screen offers a choice. In the wave 40 screenshot, two cards show named units, Hunter and Eagle General, and a third card offers a "Legendary Tier Lucky Summon" with a note that it can summon a guardian at a 25% chance[1]. That is the loop in miniature: take the sure thing or gamble for more.

The Japanese title spells out the structure more plainly than the English one. It is ラッキー傭兵団：協力ディフェンス, roughly "Lucky Mercenaries: Co-op Defense"[4]. In Korea the co-op side has grown its own culture. Between 4:07 and 5:39 p.m. Korea time on September 27, 26 of the 50 newest posts on the official Naver cafe went to a board called "co-op and bus matching"[5]. A "bus" is Korean gaming slang for a strong player carrying a weaker one through a hard difficulty.

What the September update added

Version 2.0.13 arrived on September 23. Its notes introduce a new guardian, Emily, with an Immortal form called Fairy Queen Emily that can be leveled and limit-broken and has a limited skin. The update also opened a Mid-Autumn event and a mode called Lucky Game Paradise, where up to four players face off at random[4].

The App Store event card for the update says that simply logging in grants the Mythic guardian Emily[1]. Google Play's US listing shows the same event ending on October 13[3].

The update pace is steady. The official cafe's patch-note board lists version 2.0.0 on May 21, 2026, timed to the second anniversary, and fourteen update notices through 2.0.13[5]. Google Play shows more than 5 million downloads[3].

What it charges in dollars

The game is free to download and shows ads[3]. The ten in-app purchases listed on the US App Store page are these[1]:

• Starter Package 1 and Upgrade Trigger Package 2: $3.99 each
• Upgrade Trigger Package 1: $4.99
• Wave Pass, Scroll Trigger Package and Starter Package 2: $6.99 each
• VVIP Package: $9.99
• Upgrade Trigger Package 3 and Wave Trigger Package 1: $11.99 each
• Upgrade Trigger Package: $19.99

Google Play's US listing puts individual items between $1.99 and $109.99[3]. Apple rates the game 13+ in the US and lists loot boxes, advertising, messaging and chat, and infrequent simulated gambling[1]. Google Play rates it Everyone, with mild fantasy violence and in-game purchases that include random items[3].

The odds, in Korean

111 Percent publishes drop rates on a standalone page, linked from the menu of the official Korean cafe[6]. It has six groups: hero recruitment, treasures and altar, Immortal limit breaks, relics and blob figures, pets, and runes. Every label on it is in Korean, and requests for English data paths on the same site returned "not found"[6]. If you play in English, you will need a translation tool to read it.

The numbers are worth the effort. In hero recruitment, a Mythic hero appears 1.8519% of the time. Once it appears, it has a 5% chance of passing the castle gate and joining you[6]. Multiplied together, that is about 0.09%, or roughly one Mythic per 1,080 recruitment presses.

Pet draws change with a "pet draw level." At level 1, every Legendary, Mythic and Immortal pet is listed at 0.0000%. Only on the maximum-level table do the two Immortal pets appear, at 0.15% each[6]. Limit-breaking an Immortal guardian succeeds 70% of the time at level 16 and 1% of the time at level 25[6].

February 5

The "LUCK IS FAIR!" line got heavier this year. On February 5, 2026, the official cafe posted two notices in a row, one about a probability issue and one about compensation for it[5].

According to the Korean outlet Inven, 111 Percent admitted that day that part of its probability system had behaved differently from what was designed. The studio said it had found defects in random number generation and in how probabilities were resolved, published the code before and after the fix, and apologized[7]. On February 6 it gave every player 10,000 gems and raised pet counts across the board. Direct refunds for cash purchases were not part of the package, which drew criticism from players[7].

Two outside bodies became involved. On February 10, Korea's Game Rating and Administration Committee said it was preparing its own fact-finding review[7]. On February 13 the Korea Game Users Association reported five companies, 111 Percent among them, to the Fair Trade Commission for alleged violations of e-commerce law, with 863 Lucky Defense players delegating their claims to the association[8]. We did not find any report of an outcome from either body.

The odds page itself dates to this period. A cafe notice on February 12 is titled as an update and probability page announcement for the Lunar New Year[5].

September brought a different problem. On September 7 the cafe posted a notice on sanctions for accounts using unauthorized programs[5]. Money Today reported on September 10 that two accounts had been permanently banned and removed from the rankings for exploiting the rune system with such a program, and that the studio said both were sellers and no buyers were found[9].

Who this is for

Lucky Defense! suits people who enjoy short, noisy co-op matches with a partner and who find the slot-machine moment of a summon fun rather than stressful. The hardware bar is low. The iOS version is 1.8GB, needs iOS 15.0 or later, and also runs on Macs with Apple M1 or later. Google Play lists Android and Windows[1][3]. There are eight interface languages, including English[1].

It is a poor fit if you want to avoid randomized purchases or ads, since both are built in. The February episode is also worth weighing. The studio disclosed the error on its own and showed its code. Players who had paid cash, however, were compensated in game currency.

If you install it, do two things in order. Log in before October 13 to collect Emily. Then, before any purchase, run the pet table at level 1 through a translator and look at the column of zeros under Legendary and above. It tells you more about how fair the luck is than the tagline does.

Sources

[1] Apple. Lucky Defense! App Store page (US). Accessed September 27, 2026.

[2] Apple. App Store top-grossing and top-free game charts, RSS (Korea shown; Taiwan, Japan and US checked with the same feed). Accessed September 27, 2026.

[3] Google. Lucky Defense Google Play page (US). Accessed September 27, 2026.

[4] Apple. iTunes Search API lookup, id 6482291732 (US storefront; Japan checked with country=jp). Accessed September 27, 2026.

[5] 111 Percent. Lucky Defense official Naver cafe, notice and board listings. Accessed September 27, 2026.

[6] 111 Percent. Lucky Defense probability information page. Accessed September 27, 2026.

[7] Inven. Game Rating and Administration Committee prepares review of Lucky Defense probability error (Korean). Published February 10, 2026. Accessed September 27, 2026.

[8] Yonhap News TV. Game users association reports five companies to the Fair Trade Commission over loot boxes (Korean). Published February 13, 2026. Accessed September 27, 2026.

[9] Money Today via Daum. Lucky Defense rune hack controversy, 111 Percent issues permanent bans (Korean). Published September 10, 2026. Accessed September 27, 2026.