Wolf of 0ad Street - Market pump exploit

[Seleucids]

Under certain conditions, the market can be pumped exploited with OP trades that will generate infinite resources. Below is one example of the exploit:

One needs to firstly invest 3000 metal to buy some other resources, e.g. food, to really depreciate the metal value and raise the food value. Then you take 500 food to trade back more than 3000 metal - you end with a net profit in metal. Furthermore, the food is still highly valued and you can buy huge quantities of other resources with food, resulting in resources being generated from nowhere. 

However, this is not consistently working. I tried to reproduce this but did not get these profitable values like Cube did. After many trades, I was eventually able to generate 10K metal after spending 2000 food and 2500 wood (profit?)

 

Ideally we make changes to the bartering mechanism to prevent this from happening. 

[Stan`]

See: https://gitea.wildfiregames.com/0ad/0ad/issues/8051

[Atrik]

Since that happened this WE I looked into it, and got a grasp of the problem. The prices are currently driven by the number of transactions and not the volumes they generate. So one can drive the price of a resource then benefit from large transactions, therefor overall generating resources. Currently the formula multiply some constants to sold amount (which is equivalent to number of transactions, as sold amounts are fix), if you change it to bought amount, large transaction affect the price more, and generating resources from this 'Pump and Dump' no longer works  
=> The only way to have barter efficiency over 100% will now be if ANOTHER player oversold a resource, and the amount you can generate is now proportional to the amount he lost. Which is very likely the behavior intended in the first place.

Edited June 9 by Atrik

[Stan`]

This is an OOS change so maybe could be tested in @borg-'s balancing mod or the Com mod by @real_tabasco_sauce

[ffm2]

Today, almost 2 month after the public knowing of the market exploit, it happened again. It was a tg 4v4, the oddity detector called it out immediately. The player accused me of lying and insulted me. I wanted to resign the game right away. There was some doubt about a false positive and I carried on since the others wanted to play it out. I wouldn't post if he didn't deny it and insult me. If you are around him don't talk about any game weaknesses, exploits or modding or so. Here's screenshots from the replay. I am very disappointed that jagsusindia cheats and robs the trust and time of 7 other players. 

The oddity detector has some false positives on the other checks, e.g. for mouse clicker on lag. But I didn't see the market exploit check fail yet.

It can be seen in the snippet that jagsus only traded food and wood with a barter efficiency over 100%.

[Deicide4u]

32 minutes ago, ffm2 said:

Today, almost 2 month after the public knowing of the market exploit, it happened again.

That's sad. But that problem has a solution. 

The moment it happens, you just collectively let a 4v1 on the cheater.

Until he's out of the game, everyone is on cease fire.

Edited 18 hours ago by Deicide4u

[TheCJ]

@Arup ? Even a child should know thats not okay. Or do you have anything to say for yourself? 

[Arup]

1.Consider this: It was a champ cav game, I needed food, not wood, but I traded for wood instead of for food; so I reversed my dealings. is that cheating?

2. this is a pretty much a net loss. 2800 food+2500 wood (5300 resource total) for 4500 food is a net loss, it's barely a profit for 5900 total resource. on what earth is that cheating?

3. you need atleast 3.5k metal to run the exploit I think, and I literally started mining metal.

4. I already knew there are specs watching, do you really think I'm that dumb to actually exploit?

 

[Arup]

I was about to report it myself in that game that got a free turnover, but then ffm started spamming "gg cheats" "gg bye" "resigning" so I lost my cool. then they paused for 5 mins ruining my build. truly a great strategy, I must add.

To everyone other than ffm, I apologise if you thought this was cheating, it isn't, I'm always a texter you'll see me text my intentions always before going for smth weird or new. 

[Deicide4u]

5 hours ago, Arup said:

I was about to report it myself

Sure you were. When you bartered 500 wood for 1352 food, did you stop to think how this might be suspicious? 

No, you kept bartering 500 wood for obviously large amounts of food. 

So, I call BS. 

[alre]

may I suggest that this problem is patched by using a proper market maker algorithm in the game instead of one that's improvised? constant product is one that immediately jumps to my mind, that is actually applied in solutions with real money involved.

[TheCJ]

6 hours ago, Arup said:

you need atleast 3.5k metal to run the exploit I think, and I literally started mining metal.

You dont need any metal if you arent exploiting for metal.

I am also willing to believe that Jagsus actually bartered in the wrong direction on mistake, I made that error multiple times myself.

@ffm2 I understand that such moments can be heated ingame, but if what Jagsus says about what you said ingame is true, please try to be a bit "nicer". Same goes for @Arup of course. Its "just" a game, so long as there is a possibility that Jagsus made a mistake, you are all still on the "same side", trying to have fun playing this great game together.

 

Also @Arup , maybe just dont use the bartering system at all as long as it remains broken? The exploit makes it obvious, but even normal bartering is probably unfair is some cases.

[ffm2]

23 minutes ago, TheCJ said:

@ffm2 I understand that such moments can be heated ingame, but if what Jagsus says about what you said ingame is true, please try to be a bit "nicer".

No. The market exploit is a deal-breaker and grounds for ending the game. The only reason I stayed was out of respect for the rest of the other players. This behavior needs to be addressed immediately. The person responsible should see a direct link between their actions and the consequences.

There's nothing funny about this exploit. It just generates resources. For it to happen randomly is extreme rare but additional to that he was straight booming aiming for a market directly after reaching phase 2. Directly when the market was finished this "accident" happened.

There's only one mistake: jagsus started traded with 500 food for wood instead of 100 food but corrected it shortly after and ended up with profit.

No player aiming for champ cav stores thousand of res at minute 10 so he can spend it on champs later.

You can watch the replay. Don't play in to his delusions. I don't plan to play with him in the near future if this is not addressed properly by him. One problem is the cheating, the other is the behavior afterwards.

2025-07-26_0002_jagsusindia.zip

[Atrik]

1 hour ago, alre said:

may I suggest that this problem is patched by using a proper market maker algorithm in the game instead of one that's improvised? constant product is one that immediately jumps to my mind, that is actually applied in solutions with real money involved.

Yes, it's just a small mistake of using a wrong variable for price calculations to make it alike a constant product market maker.

Well... More or less since there is also the orders themselves that you get for the price of the first resource bought (if you buy 500 food, you get the whole 500 food for the price of the first food unit), however this will always be smaller then the base barter malus. So really we just need to fix what I'm linking to, in the above.

[Arup]

4 hours ago, Deicide4u said:

Sure you were. When you bartered 500 wood for 1352 food, did you stop to think how this might be suspicious? 

No, you kept bartering 500 wood for obviously large amounts of food. 

So, I call BS. 

 You just lost all your wood.

will you wait for someone in enemy team to look at that and take all your 3k wood? or will you take back your wood first then speak? and in anyway i do remember stalling a few seconds before doing that first trade, realising my mistake

[Arup]

2 hours ago, ffm2 said:

No player aiming for champ cav stores thousand of res at minute 10 so he can spend it on champs later.

I do! its not my fault you dont! I do lmao

[Arup]

Here is me stacking res preparing for cav champs

[Arup]

Here is the market for the same: