Case study · Wooden Sword Games

How Wooden Sword Games Tested Mystic Duel Without an SDK

Wooden Sword Games runs BugHunter by Nodemori on Mystic Duel: Card Battler CCG, straight from the public store build, with no SDK and no changes to the game. The agent completed the tutorial, won a full battle and mapped 23 screen states.

Testing returned:

Recorded sessions. Every free-play session came back with its video and console logs.
Test cases. Plain-English steps with expected results, checked on the live game.
Visual findings. In three free-play sessions run by the Nodemori team, an automatic re-check kept 7 of 12 flags, 6 distinct issues. No human verdict is recorded yet.
Regression replays. Five of five passed with zero AI calls. Each was one or two steps long.

Studio: Mobile, registered in London
Game: 1v1 merge card battler
Platform: Mobile: iOS and Android
Integration: None

Three Mystic Duel phone screens from one run: the agent dragging a red card next to its red hero, a battle board taking damage, and a You Win victory screen. — BugHunter on Mystic Duel: one drag to merge, then all the way to You Win.

changes to the build: straight from the store

screen states mapped with no instructions

7 / 12

flags kept by an automatic re-check in Nodemori's sessions: 6 distinct issues

5 / 5

short replays passed: one or two steps each, zero AI calls

Why Merge Play Trips Up Scripted Bots

Wooden Sword Games is a mobile game studio registered in London. Its games include Puzzle Wars: Heroes, a match-3 RPG with competitive PvP, and smaller hybrid-casual titles such as Snack Bag and Snail Wars.

In Mystic Duel, three cards sit face up in the centre row and each player has four slots. Same-colour cards of the same rank merge into stronger heroes. Placing a card triggers an automatic attack, and abilities unlock from merge rank 2.

For a player, that is the fun. For a scripted bot, it is a row of traps: drags instead of taps, colour and rank rules on every move, a turn to read, and a lives gate that locks battles for hours after a loss. Beyond combat lie hero upgrades, leagues, Trophy Road, chests and a shop with secure store payment screens. The agent learned merge play from a short action specification, not a script.

Dealt In Early

BugHunter was playing Mystic Duel before there was a contract. It ran its first test cases, won a full battle, and then a scout run cleared the whole tutorial.

Four Mystic Duel screens from one scout run through the tutorial, numbered and labelled Learn to play, First battles, Tutorial won and New hero. — One scout run through the tutorial: the first lesson, the battles, the final win and a new hero unlocked.

The team settled on the public build, and BugHunter installed it straight from the store. The first package followed: two gameplay videos, a generated design document and two specifications.

With that package in hand, the studio described what it wanted next. Watching thousands of playtest videos was not an option.

Brief an agent the way it briefs a tester.Delivered
Plain-English test cases for a battle with Settings and exit, a purchase flow and opening the Shop.
Play chosen situations to check balance.Still a goal
Log wins and losses by league.Still a goal
See the game on different screens without owning a hundred devices.Still a goal

One of the four requests is delivered. There is no record yet of batch balance runs or league logs, and in Wooden Sword's workspace Mystic Duel has run on one build and one device configuration.

Then came a dedicated environment with Mystic Duel installed and its specification preloaded, a live onboarding session with the studio's team, and a test-payment account so purchase flows could be tested without real charges. Today Wooden Sword runs BugHunter on a paid subscription.

“I needed to see it work without integration. BugHunter installed Mystic Duel straight from the store, with no SDK or special build. Before any contract, it was already merging cards and had won a full battle. That made me take it seriously.”
Sergei Orlov, CEO and Founder, Wooden Sword Games

Four Ways the Agent Works the Board

01Let it explore

With no instructions, the agent goes screen by screen. Its findings feed a structured specification and a design document. Point it at a competitor's title and the same mode turns into fast deconstruction.

Four Mystic Duel screens from one scout run, numbered and labelled Heroes, Shop, Reward and League. — Left to explore with no instructions, the agent found heroes, the shop, a chest reward and a league result.

02Let it play

BugHunter reads the cards, drags them into slots, merges same-colour heroes and uses abilities. In the battle at the top of this page, a red card slides in beside a red hero, they merge, and the battle ends on You Win with +5 trophies.

BugHunter console, Run Results for a Mystic Duel free-play session: mode, run and game tags, the session video of a PvP battle, and buttons to download the video and console logs. — Every free-play session comes back with its video and console logs, ready to review.

03Write the test like a tester's brief

Each step has an expected result that the agent checks on the live game. When it could not find a button, it stopped and named the missing element instead of guessing: “The settings button is not present on the current screen.”

Start a battle
Open Settings
Exit
Expect You Lose

Run Results panel for a passed test execution: three plain-English steps (start a battle, open settings, exit), each with its expected result, and no bugs. — A plain-English test case, checked step by step on the live game. This run passed with no bugs.

04Record once, replay on demand

A passing test, or a playthrough a tester records by hand, becomes a replay that runs with zero AI calls. On Mystic Duel the five replays were short, one or two steps each, and all five passed.

Console table titled Runs History with five passed Mystic Duel runs, one per mode: scout, free play, test execution, recorded regression and manual, with duration and findings. — Every run is logged with its mode, status, duration and findings.

What Three Free-Play Sessions Found

Free play is not a demo mode. While the agent fights battles and walks the menus, it watches the screen for anything a player would notice. A second, automatic review then re-checks each flag and keeps it as a bug, marks it unclear or rejects it as a false positive.

The sample is three free-play sessions on the public 1.5.5 build, run by the Nodemori team on its own account over one week. They did not run in Wooden Sword's workspace. The agent raised 12 flags. The re-check kept 7 as bugs (58%), marked 4 unclear and rejected 1 as a false positive.

Kept means accepted by that automatic re-check. It is not a developer confirmation: no tester or developer has recorded a verdict on these flags, and no triage by the game's developers is recorded. Each kept flag has a screenshot and a video clip, so a tester can check it against the recording.

flags in 3 free-play sessions over one week

58%

kept as bugs by the automatic re-check: 7 of 12 flags, 6 distinct issues

7 / 7

kept flags came with a screenshot and a video clip

text issues

layout issue, flagged at two consecutive steps

render flag from a single frame

flags not kept: 4 unclear, 1 false positive

Two of the 7 flags are the same header overlap, captured at two consecutive steps, so the 7 flags describe 6 distinct issues. The agent rated all 7 not critical. The render flag rests on a single frame that may show an animation in progress, so it is counted but not shown below.

Two Issues, Step by Step

Two of the 6 issues, with the path the agent took to reach each one, from its step trace. The screenshots are crops of the ones the agent saved with each flag, with outlines and blurring added.

Mystic Duel main screen during the tutorial, with the speech bubble Now you can equip item on you hero outlined in red and other players' names blurred. — A missing article and a wrong pronoun in a tutorial line. Other players' names are blurred.

Text

Grammar Errors in a Tutorial Line

Main screen, at the tutorial step that points to Heroes.

Steps the agent took

On the main screen, claim the Stone League reward.
Open the chest with Open All.
Claim the new hero, Kieran the Assassin.
Close the Get More Gems offer.
Read the tutorial line that appears as the tutorial points to Heroes.

Expected: The line reads “Now you can equip an item on your hero.”
Actual: The line reads “Now you can equip item on you hero”: the article is missing and “your” is written as “you”.

Status: Kept as a bug by the automatic re-check and rated not critical by the agent. No human verdict and no studio triage are recorded.

Mystic Duel hero screen: the title Bastian the Revenant, Level 10 is outlined in red where it covers the player name and gold counter in the top bar, and outlined in green in its place inside the hero panel. — In red, the hero title over the top bar. In green, the same title in its place in the hero panel.

Layout

Hero Title Drawn Over the Top Bar

Heroes, the hero panel of Bastian the Revenant, during the equipment tutorial.

Steps the agent took

In the equipment tutorial, open Heroes, open a hero card and tap an equipment slot.
Tap Shop and buy Heavy Armor Lvl.8.
Go back to Heroes and open Bastian the Revenant.
Tap the shield slot to open Inventory.
Look at the top bar.

Expected: The top bar stays readable, with the player name and the gold counter visible. The hero title appears only inside the hero panel.
Actual: “Bastian the Revenant” is drawn over the player name and “Level 10” over the gold counter. The same overlap was captured at two consecutive steps and logged as two flags.

Status: Kept as a bug by the automatic re-check (two flags, one issue) and rated not critical by the agent. No human verdict and no studio triage are recorded.

The other three text issues are a Trophy Road line, “Finish all path and you can get main prize!”, and two lines with backticks in place of apostrophes: “Let`s go to the shop” and “your hero`s stats”. All 5 flags that were not kept were about promo pop-ups that open after a reward or after closing another offer.

What the Agent Brought Back

Across BugHunter's runs on Mystic Duel:

Zero integration work.
The public store build, as players get it: no SDK, no hooks, no special build.
Playing before the contract was signed.
Test cases, a won battle and the whole tutorial.
A map of the game.
23 screen states and 29 recorded transitions, from the tutorial to the shop. The specification lists seven game modes and six resources.
Seven flags kept by an automatic re-check.
Three free-play sessions run by the Nodemori team raised 12 flags. The re-check kept 7, which describe 6 distinct issues, each with a screenshot and a video clip. None has a human verdict yet.
Five of five short replays passed.
Each one or two steps long, 30 to 41 seconds, with zero AI calls. Three ran in Wooden Sword's own workspace.

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