[jerf]

On the blockchain, accounts have a certain amount of currency.

You can issue a command to transfer currency from your account to somebody else's, as that is a primary use case of a cryptocurrency. There was a code path where you could send someone negative amounts of the currency and it would happily pay them a negative amount of currency and charge you a negative amount of currency, thus transferring their account balance to your against their will.

There were several transfer paths and I think not all of them were vulnerable, but only one has to be. There's a bit of indirection that made it somewhat less obvious than my description makes it sound, though it amounts to the same thing in the end.

[schoen]

> There was a code path where you could send someone negative amounts of the currency and it would happily pay them a negative amount of currency and charge you a negative amount of currency, thus transferring their account balance to your against their will.

This is a bug I remember from the Apple II game "Taipan" (in which you play an 1800s opium-and-silk trader in East Asia). You could borrow negative amounts of money from a lender who charges extremely high interest. As a result, the lender would quickly end up owing you tremendous sums, without your having to do anything else. Wikipedia mentions this:

> Note: A bug in the original game allows the player to overpay the moneylender, acquiring "negative debt". This "negative debt" will accumulate interest very quickly, and will count towards the player's net worth. As the game's vocabulary of number words ends at "trillion", this can cause the game to display garbage instead of the player's correct net worth. This has been fixed in the online "for browsers" version of the game.

[pennybanks]

it really shouldnt be referred to as currency as a whole anymore.

well i guess anything can be a currency but its too misleading even though that was by design.

if its designed to be a stock then should be called so. poker chips? in game currency? money laundering token? reward points? purchase receipt? jpeg? just think it would help

[nailer]

'Token' is the generic term people have settled on. 'Currency' is rare.

A stock would be a 'tokenized equity', in the same way there's 'tokenised real estate', 'tokenised metals', 'tokenised bonds', whatever the real world asset is.

'In-game currency' is indeed used by gaming people, since that was their term from before blockchain.