Nicholson, who has ridden at all six world games, for a best result of a bronze in Kentucky four years ago - when New Zealand also won the bronze - will ride either Nereo or Avebury.
Double Olympic champion Todd will ride Leonidas, and Price is on his favoured mount Wesko.
Two riders have been named to contest the individual event, Caroline Powell on Onwards and Upwards and Lucy Jackson and Willy Do.
The team reserves are Jonelle Price on Classic Moet, Tim Price on Ringwood Sky Boy and Megan Heath on St Daniel.
Nicholson and Todd were in the team which won gold at the games in 1990.
High performance eventing coach Erik Duvander says the team combinations are all well proven, but he cautioned it was still all about putting it together on the day.
"We have an incredible amount of energy in this team and we have super talented horses," Duvander, also eventing chef d'equipe for the games, said.
The eventing will take place from August 28-31. The Games run from August 23 to September 7 and a record 72 nations are expected to take part.