Robots from 31 countries went head to metallic head in football and other competitions with a goal of triumphing against human soccer champions -- after 50 years or so of practice.

　　Researchers in ties and people in uniforms matching their machines stood alongside the robots which vied for titles in the weeklong RoboCup 2005 being held in the western Japanese city of Osaka.

　　Among other competitions, teams face off in RoboCup Rescue in which they show the search and rescue skills of their machines such as the speed and stability of going down stairs.