Negative Testing

Enter forbidden words
┗ Slander, insults
┗ Obscene expressions
┗ Personal info such as phone numbers, addresses

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⇒ Inappropriate words are displayed in the game

Enter SQL statements or scripts
┗ select * from users;
┗ ＜script＞alert('xss')＜/script＞

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⇒ Database or screen attacks succeed, causing data leakage or destruction

Enter beyond character limit
┗ Paste long texts
┗ Insert大量 line breaks

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⇒ Text overflows display area and UI breaks
⇒ Input processing becomes heavy and freezes
⇒ Error occurs when saving to server

Enter emojis or special characters
┗ 🍎😊💲🌊 unsupported font characters

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⇒ Unsupported font causes garbled text
⇒ Processing error occurs on server side

Submit empty (null)
┗ Leave name field blank
┗ Enter only spaces or line breaks in required fields

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⇒ Required fields remain empty but are still registered

Enter values with invalid format
┗ Mail: aaa@@bbb.com
┗ Phone: abc-1234-5678

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⇒ Exception occurs during input conversion, processing fails

Register duplicate info in a form with unique constraint
┗ Enter same name as existing user

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⇒ Duplicate registration occurs, causing data consistency errors

Increase digits until display or processing limit is exceeded
┗ Excessively increase experience points
┗ Excessively increase money

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⇒ Numbers overflow the display area
⇒ Calculation overflow produces abnormal values

Add values beyond the upper limit
┗ Gain more currency or experience beyond the maximum
┗ Combine buffs and items to break stat caps
┗ Purchase items beyond maximum possession

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⇒ Numbers or inventory counts become invalid
⇒ Errors occur in display or calculations

Subtract values beyond the lower limit
┗ Attempt purchases with insufficient funds
┗ Combine debuffs and items to break lower stat limits

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⇒ Negative or invalid values occur
⇒ Calculations or progression conditions collapse

Exceed upper or lower bounds of time limits
┗ Make remaining time negative
┗ Continuously extend remaining time

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⇒ Event no longer progresses
⇒ Remaining time effectively becomes infinite

Trigger truncation of calculated values (decimals)
┗ Truncate fractions in experience calculation
┗ Truncate fractions in damage calculation

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⇒ Totals no longer match
⇒ Minimum should be “1” but truncated to “0”

Repeatedly press purchase or confirm button

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⇒ Process is executed twice
⇒ Items obtained multiple times
⇒ Duplicate payments occur

Select multiple buttons slightly offset in timing
┗ Quickly press YES/NO buttons in succession
┗ Quickly press multiple selection buttons in succession

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⇒ Multiple processes are executed simultaneously
⇒ Contradictory actions occur at the same time

Meet multiple event start conditions at once
┗ Starts when hit by explosion
┗ Starts when hit by ranged attack
┗ Starts at a scheduled time

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⇒ Multiple events start simultaneously, breaking progression or cutscenes

Become defeated during an event scene

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⇒ Event continues while defeated
⇒ Game over sequence interferes with event sequence

Enter event start area while simultaneously defeated
┗ Defeated by status ailment damage
┗ Defeated while being blown away by attack
┗ Defeated by fall damage from height

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⇒ Event starts while in defeated state

Become defeated immediately after clearing a condition
┗ Fall into a pit right after reaching stage goal
┗ Defeated immediately after completing mission

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⇒ Condition cleared but reward not received (retry impossible)

Change screen immediately after clearing condition
┗ Jump to another stage right after clearing
┗ Move to adjacent area right after clearing

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⇒ Condition cleared but reward not received (retry impossible)

Recover HP after being defeated
┗ Recover HP with ally support
┗ Recover HP by using item
┗ Auto recovery on level up after defeat

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⇒ HP is restored and revived but game over sequence still continues

Make opposing factors coexist simultaneously
┗ Combination of 100% hit rate and 100% evade rate

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⇒ An attack with 100% hit rate does not land
⇒ Attack lands on an opponent with 100% evade rate

Returning to normal size in an area restricted to small characters
┗ Enter as small and revert to normal size
┗ Revival from defeat cancels small state
┗ Cancel small state via save & load

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⇒ The premise of “small-only” restriction collapses

Take damage while invincible and become defeated
┗ Suffer status effects like poison
┗ Take fall or terrain damage

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⇒ Invincibility effect is ignored, leading to defeat

Take damage and become defeated in a safe zone
┗ Damage from poison or self-destruct items
┗ Ranged attacks reaching the safe zone
┗ Taking damage from being crushed by objects

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⇒ Defeated in non-combat areas
⇒ Defeated in bonus stage

Cause undroppable items to disappear
┗ Sell at shop
┗ Delete via trash bin
┗ Transfer to NPC or other members
┗ Give to leaving member and lose
┗ Use as synthesis material
┗ Drop due to defeat or death penalty

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⇒ Lose essential item for clearing, progression impossible

Apply mutually exclusive states simultaneously
┗ Take fall damage while floating
┗ Both poison damage and continuous HP recovery active

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⇒ Effects conflict, causing unnatural behavior

Change event order, breaking story consistency
┗ A character already dead appears in another event
┗ Dialogue of an untriggered event is spoken earlier

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⇒ Event order and story consistency are lost

Touch/swipe empty areas

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⇒ Objects that shouldn’t exist respond
⇒ UI or scene transitions malfunction

Use a skill/item when no target exists
┗ Cast healing magic with no target
┗ Activate attack skill with no enemy

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⇒ Can be used despite no target
⇒ Effects and animations become unnatural

Use important items at inappropriate timing
┗ Use story-required item in unrelated scenes

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⇒ Important items disappear
⇒ Event progresses unnaturally

Perform actions that benefit enemies
┗ Heal enemies with recovery items
┗ Attack allies

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⇒ Behavior and balance become unnatural
⇒ Battle progression becomes unintended

Stack objects on top of each other
┗ Place a character on top of another
┗ Place objects on moving ones (vehicles, etc.)

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⇒ Repeated falling motion (abnormal behavior)
⇒ Enter areas normally unreachable

Become defeated in unusual posture
┗ Defeated while climbing a ladder
┗ Defeated while riding a vehicle

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⇒ Falling animation occurs midair, causing unnatural display or judgment

Proceed in events without required items
┗ Store axe in warehouse, then forced into “area requiring axe”

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⇒ Progress impossible due to missing required item

Move character coordinates to abnormal positions
┗ Character flies off-screen due to jump or knockback
┗ Push enemies off-screen

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⇒ Cannot return to original position
⇒ Cannot defeat enemies outside screen, making clear impossible

Create mismatch between special effect timing and overall game progression speed
┗ Start event in slow-motion state
┗ Start event in accelerated state

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⇒ Only the player moves in slow motion during event
⇒ Only the player moves at accelerated speed during event

Save while buff is active
┗ During attack power boost
┗ While invincible

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⇒ Effect continues after resuming
⇒ Or effect is immediately canceled

Save while debuffed
┗ Poison
┗ Slow

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⇒ Effect continues after resuming
⇒ Or effect is immediately canceled

Save in a special state
┗ Miniaturized state
┗ Animal form

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⇒ After resuming, appearance is normal but hitbox remains transformed

Save while riding a mount
┗ Car
┗ Animal

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⇒ After resuming, player stands inside the vehicle
⇒ After resuming, the vehicle disappears

Save during event playback

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⇒ After resuming, the cutscene plays twice
⇒ Or cutscene does not play and only flags progress

Save during an action or effect
┗ While jumping
┗ During skill animation
┗ During defeat animation

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⇒ Character position shifts after resuming
⇒ Player becomes unable to control

Save during stage or phase
┗ During boss battle
┗ During bonus stage

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⇒ Enemy AI does not work after resuming
⇒ Animations remain frozen

Save while connection is unstable

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⇒ Flags or data saved incompletely, causing inconsistencies after resuming

Disconnect during loading
┗ Disconnect network during stage load

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⇒ Unable to reconnect
⇒ Data corruption occurs

Disconnect immediately after purchase
┗ Disconnect right after item purchase confirmation
┗ Disconnect right after gacha execution

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⇒ Obtain items without reducing currency
⇒ Data integrity is broken

Disconnect right before/after synchronization
┗ Disconnect right after item acquisition
┗ Disconnect right after quest completion

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⇒ Only items/rewards are applied, consumption or condition updates are skipped
⇒ Data rollback occurs

Disconnect at the moment of certain defeat
┗ Disconnect during multiplayer right when defeat animation plays

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⇒ Avoid losing win rate or rating
⇒ Match records are not saved properly

Disconnect after match is confirmed
┗ Disconnect right after opponents or raid members are determined

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⇒ Team disbands including opponents
⇒ Match attempt count does not decrease

Use network delay tools or environments
┗ Cause artificial delay or packet loss via network emulator

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⇒ Only part of synchronization is processed, leading to inconsistencies
⇒ Exploits possible using desync (teleporting, disabling attacks, etc.)

Move device time forward
┗ Enable playing pre-start events
┗ Claim daily login rewards multiple times

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⇒ Bypass wait times and date restrictions, disrupting progress balance
⇒ Undermines design intentions of monetization and time-based mechanics

Move device time forward
┗ Instantly remove skill cooldown
┗ Instantly complete building or crafting
┗ Continuously watch ads with wait times
┗ Fast-forward time-based recovery of action points

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⇒ Perform restricted actions consecutively
⇒ Game progress and balance collapse

Move device time backward
┗ Extend buff duration
┗ Extend lifespan of time-limited items
┗ Purchase daily paid items multiple times

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⇒ Original limits and deadlines become meaningless
⇒ Items and effects can be used indefinitely

Avoid restrictions by changing time zone
┗ Shift date reset or update checks
┗ Obtain daily content multiple times

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⇒ Daily limits and time-dependent events can unintentionally be executed multiple times