What was the world champion rugby team in 2018?
2018 Rugby World Cup Sevens
New Zealand
The 2018 Rugby World Cup Sevens was the seventh edition of the Rugby World Cup Sevens. Organised by World Rugby, it was held at AT&T Park in San Francisco, United States. A total of 84 matches (52 men's and 32 women's) were played over three days from July 20–22, 2018 with both tournaments being played for the first time in a knock-out only format.[1] 
New Zealand won the championship for both events — defeating England in the men's final and France in the women's final.