Item Duplication Incident

Item Duplication Incident - Full Report and Resolution

Date: 2026-06-27, 20:21 server time
Status: Server temporarily closed after an item duplication exploit - investigation and cleanup complete; final verification underway ahead of reopening.
Last updated: June 29, 2026

This report explains the item duplication ("dupe") exploit that led us to take the server offline, what we found, how we fixed it, and exactly what we are doing to restore the integrity of the economy. We have tried to be as transparent as possible.

Summary

• A small group of accounts abused a bug in the Master Storage system to duplicate items, then converted many of those items into zeny by selling them to NPCs and to player shops.
• The abuse was minor for most of its roughly six days, then escalated into a large "finale" in the final hours - and that finale is almost entirely undone by the backup rollback, so the bulk of the damage has been reversed from the rollback alone.
• We closed the serverto stop further damage and to preserve the evidence needed for a clean recovery.
• The underlying bug has been identified and permanently fixed.
• We are restoring the server from a backup taken shortly before closure and removing the duplicated items and ill-gotten gains from the accounts responsible.
• The accounts involved are permanently banned.

We know how damaging dupes are to a server's economy and to your trust. Thank you for your patience while we made sure the fix and the cleanup were done correctly rather than quickly.

What happened

The Master Storage system is shared across all of the characters and accounts that belong to a single master account. Because of a timing flaw, it was possible - only while the server was under heavy load - for the same stored items to be loaded and withdrawn more than once, creating duplicates.

In plain terms: server lag opened a brief window where two characters on the same master account could each open the same master storage, take the same items, and the game saved both copies. Repeating this allowed items to be multiplied.

A group of accounts discovered this and exploited it. They:

• duplicated stackable goods (refine materials, event coins, consumables, boxes and more),
• converted large amounts of duplicated goods into zeny by selling to NPCs,
• and spread some of the proceeds into the wider economy by buying out player shops and trading/dropping items.

Scope of the abuse

Our investigation reconstructed the activity from the server's transaction logs and the final database. At a high level:

• The exploit was driven by a single ring of 16 master accounts, which have been fully identified.
• Millions of duplicated items were produced across many item types.
• A large amount of zeny was created out of thin air by NPC-selling duplicated goods, and a portion of it was laundered into the economy through player shops.
• The most intense activity - a final "burst" of NPC selling, shop buy-outs, and item drops in town - happened in the last few hours before we closed the server.

The overwhelming majority of the duplicated wealth stayed within the ring's own accounts, which makes the bulk of it straightforward to remove. For a sense of scale: outside the banned ring and staff accounts, no single account holds more than about 1.5% of the total economy - and most hold far less. The exploit did not turn any ordinary player into a billionaire.

The fix

• Immediate hotfix: Master Storage was disabled the moment the exploit was confirmed, so no further duplication was possible.
• Permanent fix: This was not a simple "forgot to check" mistake - a guard against opening the same storage twice was already in place. The real flaw was a race condition across our server processes. Master Storage is owned by a separate authoritative process (the character server) and loaded asynchronously by the map server each time a storage is opened. Under heavy load, that cross-process load could lag long enough for two characters on the same account to both clear the guard before either load finished - producing two independent in-memory copies of the same storage that were then each saved. We re-engineered how shared storage is acquired and reconciled so access is now serialized and validated across that asynchronous server boundary, closing the window completely regardless of server load or latency.
• Better logging: We enabled additional item and storage logging so that any future anomaly can be detected and traced far more quickly.
• Infrastructure: Because the exploit depended on the lag that widened the timing window, we have migrated the server to a new, much more powerful host. It is faster and more stable, which removes the lag conditions the exploit relied on - a complement to the code fix, not a substitute for it.

Our decision: restore from backup + remove ill-gotten assets

We weighed three options:

• (A) Full server wipe - a complete fresh start (characters, levels, and all progress reset).
• (B) Partial wipe - keep all characters and levels, but remove every item and all zeny server-wide.
• (C) Restore from a recent backup + surgically remove the duplicated assets from the accounts responsible.

We chose option C, because it removes the damage while being the least punishing to innocent players. Both wipe options would have stripped honest players of items and wealth they legitimately earned (option A even more so, by erasing their characters entirely) - to clean up an exploit they had no part in. Restoring to just before the worst of the abuse, then surgically removing the duplicated assets, lets us undo the bulk of the damage while leaving honest players' progress and possessions intact.

Backup used: the most recent image available before closure, restored to the server's state as of 17:38 server time on Saturday, June 27 - approximately 2 hours and 43 minutes before the server's last activity (the final transaction in the database is at 20:21 server time on June 27). The worst of the abuse (the final NPC-selling and shop buy-out "burst") happened in those final hours, so restoring to just before it reverses a large share of the laundering and dispersed items while costing only a few hours of normal progress rather than any more. In fact, about 84% of June 27's large NPC cash-outs happened after the 17:38 backup point - so the restore undoes the great majority of the finale.

On top of the restore, we are removing the duplicated items and the ill-gotten zeny that remain on the accounts responsible, and removing the small number of clearly-duplicated items that had been pushed onto a few outside accounts.

What this means for you

• The final ~2 hours and 43 minutes of progress will be rolled back. Anything that happened after 17:38 server time on June 27 (levels, drops, trades, zeny, NPC purchases) will not carry over. We're sorry for this - it is the cost of undoing the worst of the abuse cleanly.
• Items you legitimately owned before that point are safe.
• If you sold items in your shop to one of the abusing accounts in those final hours, that sale (and the zeny from it) is part of what gets rolled back.
• The accounts responsible are permanently banned, and their holdings are being wiped as part of the cleanup.
• A small one-time zeny adjustment (about 10%) applies evenly to everyone - the final step that returns the economy to its proper level. Your items are untouched, and because it's the same percentage for everybody, your standing relative to other players doesn't change.

By the numbers

What we found, and how much the restore + clawback removed. Please read this clarification first: for items, the "On server at closure" figure below is the total number of units of the affected item types across the entire server - not a count of duplicates. The duplicated copies were overwhelmingly concentrated in the ring's own accounts, which is why nearly all of each type was removed.

Category	On server at closure	Removed
Affected item types - all copies (legit + duped)	~1,866,000 units	~1,599,000 removed (about 86%)
Duplicated cards (ring-held)	6,719	6,719 (all of them)
Duplicated / laundered zeny	Created out of thin air by NPC-selling duped goods	100% removed (restore + clawback, with the small remainder offset by a one-time equalizing adjustment)

Figures are rounded. The affected item types are the categories the ring duplicated - refine materials, event coins, consumables, boxes and similar. The ~14% of units not removed are not leftover duplicates - they are legitimately-owned copies (normal farmed coins, single legit items) plus a small amount that reached players through ordinary trade before the backup. We removed essentially all of the ring's duplicated copies; what remains is overwhelmingly honest player property.

Affected item types: item-by-item

We swept the entire item database - every item, every card, and every piece of equipment in the game - looking for signs of duplication. The vast majority came back clean (normal player holdings); the table below is every item type that actually turned up duplicated in quantity.

For each affected type: On server at closure is the total amount of that item type in the database when the server shut down (legitimate copies included - not a count of duplicates); Removed is the duplicated / ring-hoarded copies deleted by the backup restore + clawback; Legitimate is what stays in the game afterward - ordinary player holdings, not duplicates.

Item	On server at closure	Removed	Legitimate (still in game)	% removed
Revenant Costume Box 1	76	76	0	100.0%
Thick Battle Manual	77,989	77,987	2	100.0%
HD Elunium	106,474	106,340	134	99.9%
Old Card Album	12,178	12,170	8	99.9%
HD Oridecon	132,624	132,380	244	99.8%
Four Leaf Clover	32,120	31,156	964	97.0%
Bloody Coin	168,622	162,586	6,036	96.4%
100 Cash Point Bag	89,118	85,797	3,321	96.3%
Poison Bottle	10,097	9,572	525	94.8%
Frozen Rose	55,152	47,875	7,277	86.8%
Witherless Rose	3,467	2,986	481	86.1%
Abysmal Knight Card	161	138	23	85.7%
Gold	4,394	3,653	741	83.1%
Old Coin	618,448	496,984	121,464	80.4%
Hunting Coin	555,456	429,431	126,025	77.3%
Sheen Aura Box	12	9	3	75.0%
Valkyrie Helm Box	10	7	3	70.0%
Total	1,866,398	1,599,147	267,251	85.7%

The Legitimate column is ordinary player property. For example, the ~121,000 Old Coins still in the game are normal farmed currency spread across thousands of players (no one holds more than a few hundred) - not 121,000 duplicates. The ring's duplicated coins were hoarded on its own accounts and have all been deleted. Likewise the leftover Abysmal Knight Cards are legitimate single copies (largest holding is 3). Every duplicated item, and every valuable card, held by the ring was removed in full.

What is recovered

Category	Outcome
Duplicated items still held by the ring	Removed in full (their accounts are wiped)
Zeny created by the ring via NPC selling	Fully removed
The final-hours laundering into player shops	Largely reversed by restoring the pre-burst backup
Duplicated items pushed onto a few outside accounts	Removed where clearly identifiable
Cosmetics created in the final burst	Reversed by the backup

Restoring the economy to its proper level

The duplicated zeny was removed in two steps:

• Step 1 - wiping the ring's own accounts removed 89.6% of it. The overwhelming bulk of the duplicated zeny sat on the offenders' accounts (caught by the backup restore + the clawback) and was taken straight from them.
• Step 2 - a small, one-time, evenly-applied ~10.4% adjustment to all zeny balances removed the final 10.4%. This step was only needed for the last sliver that had spread into the wider economy.

Together those two steps account for 100% of the duplicated zeny, returning the economy to its proper, pre-exploit level.

For added peace of mind, the economy also destroys zeny on its own every day - many everyday NPC services charge zeny that is then permanently removed from the game. Over the server's lifetime, players have already spent:

Service	Zeny removed from the economy
Socket enchanting	~1.15 billion
Beelzebub Wing quest	~1.10 billion
Warp service (warps + unlocks)	~1.17 billion
Buff services	~945 million
Hunter's Assurance	~368 million
Lottery (after prize payouts)	~36 million
Stat / skill resets	~299 million
Kafra card, Soul Link, instances and more	~320 million
Total tracked zeny sinks	~5.4 billion

That is the equivalent of about half of the entire current economy drained back out through these sinks over the server's life - and it keeps happening every single day. So on top of the cleanup, the economy continuously self-corrects: zeny is always being removed through normal play.

The recovered economy: current state

For full closure, here is a snapshot of the actual database the server will reopen with, after the restore and the cleanup. The takeaway: everything looks normal. There are no giant stockpiles, no billionaires, and no leftover duplicate items.

Measure	Current state
Total zeny in the economy	~9.4 billion, spread across ~8,800 accounts
Wealthiest single account	~135 million - about 1.4% of the economy (and most players hold far, far less)
Cloned/duplicate items remaining	Zero - every provably-duplicated item was removed
Largest stack of any single card	48, and it's a common farming card; no valuable or MVP card is held in bulk
Most-held valuable card (Abysmal Knight)	largest single holding is just 3 (all legitimate)
Largest Old Coin / Hunting Coin holding	595 / 661 - ordinary farmed amounts (the ring's 30,000-stacks are gone)
Largest Bloody Coin / Gold holding	481 / 49
Total items on server	~49 million, overwhelmingly ordinary consumables, materials and gear

In short, the recovered server looks healthy and ordinary: wealth and rare items are spread thinly across the whole playerbase in normal amounts, the duplicated hoards are gone, and no single account dominates the economy.

Consequences for those involved

The accounts that took part in the exploit have been permanently banned. Exploiting bugs to duplicate items is a serious violation of the rules, and we treat it as such.

If you unknowingly bought a duplicated item or received duped zeny through normal trade, you are not in trouble - some of those items/zeny may simply disappear as part of the cleanup, but no action will be taken against you.

Accounts involved (permanently banned)

All characters listed below belonged to the exploit ring and are permanently banned. In total this is 16 master accounts, 80 game accounts, and 157 characters, run by the same group. They are listed grouped by master account:

• Mentalist, Ziahra, dupe server, ugpro, ggss, ggss2, Dealer, AmnZia, gymbro
• Eluveitie, Nightwish, HSBurn, ATRemains, HeavenSB, HPPS, Wintersun, Deathaura
• DollaBills, Mani, Pani, Teszz, Dollman, Faah, Haaf, Flaaa, Wzaas
• Daryl, Andrea, Sniper Daryl, Revenant Daryl, Merchant Daryl
• PACO MERMELIN, PACO MERMELIN2, jungle diff, YOU SURE EDDIE, PACO2, monkeyf
• Arcanna, Savage, Vulcana, Pancracio, Luthien, Verumoto, Tutty, Bellalith, Torcuato, Ghospelin Gonsales, Leire Diez, Papafrita, Xamp Jinping
• Kutxazain, Saltzailea, Sendatu, JulioIglesias, Irene Montero, PacoDeLucia, DuaLipa, Steel Crow
• Nicole Lee, Priscilla
• Ragmariz, Carapan, Pistolikas, Lianne, Boticaria, Divina, Hugo Champez
• Gerrardmino, Theopr, Yawgmoth, Solbad, Zerglink, Bragi Boy, Dancing Queen, Tessebik, Jihadi Jim, TheoWS, Weatherlight, Zergling, Hydralisk, Mutalisk, Guardian, Goliath, Dragoon, Karn, Golem Karn, Zealot Overlord, Zealot
• SirPeriox, Peirox, El Dopas, Endown, TunakTunak, DuaLupa
• 2222, 1111, whocares, some man, 1112, 1113, my hero, my new hero, 1115, 1116, Star Glad, Bragiman, 1117, 1118, 1119, 1110, sp song, mvp owner, Soul Linke, Holy Power
• iroh, toph, acua, akua, enue, ende, ametsa, kadun, vende, erosi, eroski, eroski0, Alea, merc, greed 1, greed 2, greed 3, greed 4, greed 5, greed 6, greed 7, greed 8, greed9, greed 10, greed 11, greed 12, greed 13, eroski1, Amets, next
• Kennen Smurf Account, K Kauppias, Abagagaga, Kahvipannu, Hapankorppu
• Pepa, Kyoze, Aoii, Aooi, CindyNero, PAQUITO THE RAT, PACO RAT, pikaxuraton
• FREESANCHO, FREESANCHO1

Timeline (reconstructed from the logs)

All times are server time. This is what our investigation was able to reconstruct, including when each duplicated item type first showed up in large quantities.

When	What we found
June 20-21	Earliest exploit activity in the logs - unusually large NPC cash-outs begin (recurring ~11M sales, growing into the tens of millions)
June 22, 15:18	First large duplicated stacks of refine materials - HD Oridecon / HD Elunium
June 26, evening	Mass consolidation: duplicated Old Coins and Hunting Coins moved in maximum 30,000 stacks; one account cashed out ~1.84 billion zeny through NPC sales in under an hour
June 27, 00:11	Large duplicated stacks of Cash Point Bags and Battle Manuals appear
June 27, 17:00-19:30	The "finale" (peaking after 18:00): repeated massive NPC sales (individual sales up to ~397 million zeny), Bloody Coins dumped, and items dropped in town
June 27, 17:38	Backup restore point - the state we are reverting the server to
June 27, 20:21	Exploit confirmed; server taken offline for emergency maintenance (last activity in the database)
June 27-29	Full investigation, permanent fix, and recovery
(TBA)	Server reopens once everything is verified

Frequently asked questions

Will my legitimately-earned items be deleted?
No. Only items duplicated by the exploit, the offenders' holdings, and clearly-identifiable duped items on a few outside accounts are removed. Normal holdings from before the backup point are safe.

Why is my zeny slightly lower than before?
As the final step of the cleanup we applied a small one-time adjustment (about 10%) to everyone's zeny, so the server's total returns to its proper, pre-exploit level. Because it was applied equally to every player, your ranking and your buying power relative to others are unchanged - and it's a far lighter touch than the full wipe we could have done. Your items were not affected.

Why did I lose the last few hours of progress?
The worst of the abuse happened in those final hours. Restoring to just before it is the cleanest way to undo most of the laundering and dispersed items without a much larger rollback.

Why not just wipe the whole economy and start fresh?
A full wipe punishes everyone equally - including the players who did nothing wrong. Our approach removes the abuse while preserving honest players' progress as much as possible.

Could this happen again?
The specific bug has been permanently fixed, additional logging is in place to catch anomalies early, and we are improving performance so the lag conditions the exploit relied on are reduced.

What about duplicated costumes or wings?
Costumes are purely cosmetic - no stats, no advantage. We removed every costume and costume box held by the banned accounts, and the rollback reverses most of what was scattered to others. A small number reached players before the backup; because opening a costume box creates a brand-new serial, those are impossible to tell apart from legitimately-earned ones, so we've left them rather than punish innocent players. They affect appearance only.

I think I have a duplicated item / I saw suspicious activity. What do I do?
Please contact the staff team and we will deal with it immediately.

Closing

We're sorry this happened. Dupe exploits strike at the heart of a server's economy, so we tried to do this as properly as we could: we traced the abuse through the server's transaction logs, identified accounts involved, swept the entire item database to be as certain as possible that nothing was missed, and rebuilt the underlying system so this class of bug cannot recur. Thank you for your patience and for sticking with us - we'll announce the reopening as soon as the final preparations are done.

- The Revenant Elegy Team