No, the rules have not changed since France's Zinedine Zidane was infamously ousted from the final of the 2006 World Cup. Headbutting an opponent is still not allowed in soccer.
Arsenal's Olivier Giroud was reminded of this fact with a red card as his team tangled with Queens Park Rangers on Boxing Day. The 28-year-old striker was sent off in the 53rd minute at the Emirates on Friday after using his head to retaliate against Nedum Onuoha for a shove in the back.
"It was was a deserved red card, Olivier didn't control himself. It completely changed the dynamic of the game, we were completely in control at that stage and it was quite comfortable," Arsenal manager Arsene Wenger said after his team held on for a 2-1 win, via Express. "Olivier is a guy who, when he makes mistakes, he stands up and admits it."