Supernatural powers become contagious in PC game

• 18:08 07 January 2005
• NewScientist.com news service
• Will Knight

Eerie occurrences in a hugely popular computer game have been traced to rogue computer code accidentally spread between players like an infectious illness.

The Sims 2, released in September 2004, lets players assume godlike powers in a virtual community populated by characters they have created. They can influence the behaviour and fortunes of their characters in a huge variety of ways and sit back to witness the outcome.

The second edition of the game has already proven extremely popular and adds an extra dimension by enabling players to trade items, characters, even whole buildings through an online swap shop called The Sims 2 Exchange.

But in November 2004 several players began complaining that the characters and even some inanimate objects in their lovingly built worlds had begun behaving oddly. Some noticed that characters no longer aged while others found magical items - like an espresso maker that gives its user unlimited happiness - inexplicably installed in their character's homes.

Reverse engineering

The problem was traced to software "hacks", or patches, created by hardcore players who enjoy tinkering with the game at a deeper level. By "reverse engineering" the game they figure out how to develop software add-ons, or patches, to twist the game's parameters.

For example, the "No Jealousy" patch lets characters have more than one lover without either getting jealous. Other patches stop characters getting old or turn ordinary household objects into items imbued with supernatural powers.

But apparently no-one expected these patches to override the game's default features and be transmitted through the exchange.

Continual surprises

The company that publishes The Sims 2, Electronics Arts, in California, US, altered the exchange site in December to alert users to "hacked" items. The company also produced information on how to remove hacked features from games.

"Our community continually surprises us by their creativity," reads a statement issued by the company. "In some of these exchange items there may be pieces of content or modifications that a user finds undesirable to their game play. For this reason, we want to warn you if a lot contains any modified content."

But some of those responsible for creating patches also decided to tackle the problem themselves and developed a program the scans for known patches in a game, called the Sims 2 Hack Scanner and Lister.

Dave Wood, editor of UK computer games magazine PC Zone says those who modify computer games are not generally malicious but admits that someone could theoretically exploit such a loophole to cause trouble in other players' games. "It's the first time anything like this has happened," he told New Scientist.