Some of the inmates police say are behind a rampage at Spring Hill Prison in Waikato could face an extra 14 years' jail.
A total of 23 defendants appeared in the Auckland District Court on Tuesday, for the first time since the June riot, facing 41 charges.
Eight are of damaging property by fire when it ought to have been known a danger to life was likely.
That charge carries a maximum 14-year prison term.
Most of the defendants are now held at Auckland Prison at Paremoremo, and appeared by video link.
The other charges include rioting and causing unlawful damage in a riot, as well as assault, and injuring with intent.
Name suppression has been ordered for the 30-strong police witness list.
The inmates were remanded until 17 September so their lawyers can receive more information.
It is the first time the defendants have appeared in court since the riot on 1 June.
The police have been seeking suppression orders for 30 alleged victims and witnesses to protect them. Most of them are prison officers.
