Two programming teams have created intelligent virtual gamers—or "bots— that have not only beaten the Turing test, but managed to be appear more human than human gamers.

The UT^2 bot, programmed by a team from the University of Texas, and MirrorBot, programmed by Romanian computer scientist Mihai Polceanu, split a top prize of $7,000 (£4,300) at The 2K BotPrize—a contest that has been challenging programmers since 2008 to create game bots that appear to be as human as possible, playing like fallible human gamers rather than near-perfect computer AI.

In the competition, computer-controlled bots created by programming teams from all over the world face off alongside human players, who act as judges, in the virtual battle zone of Unreal Tournament 2004. Any combatant a judge meets which they believe to be human is tagged with a "judging gun." After several rounds of combat, the bot that has received the most human tags wins the contest.

While the human players managed to gain an average "humanness" rating of 40 per cent, the UT^2 Bot and Mirror Bot both achieved a rating of 52 percent. This is the first time since the contest has been run that a bot has achieved the target score of 50 percent "humanness."

"A great deal of the challenge is in defining what 'human-like' is, and then setting constraints upon the neural networks so that they evolve toward that behavior," University of Texas doctoral student Jacob Schrum told his department website.

"If we just set the goal as eliminating one's enemies, a bot will evolve toward having perfect aim, which is not very human-like. So we impose constraints on the bot's aim, such that rapid movements and long distances decrease accuracy. By evolving for good performance under such behavioural constraints, the bot's skill is optimised within human limitations, resulting in behaviour that is good but still human-like."

Fittingly, the completion of The 2K BotPrize's challenge comes 100 years after Alan Turing posited his Turning test. Now that two bots have successfully achieved a 50 percent humanness rating, the 2K BotPrize team hope to create a new challenge for bot programmers.

Should any Unreal Tournament 2004 gamers wish to take on the UT^2 bot, the team have made their prize-winning player available here.