A terrorist attack is one of hundreds of situations being imagined by police and Rugby World Cup organisers as they plan for the New Zealand-hosted tournament.
Wednesday marks 100 days until the tournament kicks off in Auckland.
Police and organisers are working with other groups to stage theoretical scenarios and work out how to overcome them.
Superintendent Grant O'Fee, the police commander of Rugby World Cup operations, says through a terrorist attack is unlikely, authorities must be prepared.
Mr O'Fee will not give details of counter-terrorism measures, but says police are speaking with other security agencies and looking at how terror threats have been dealt with overseas.
Other scenarios being prepared for include a team bus getting stuck in traffic, public transport failing, or power going out in a stadium.
The tournament begins on 9 September, with the final to be held at Eden Park on 23 October.