Individuals convicted of "serious crimes" are to be drafted into the Russian army as Moscow struggles to make headway in Ukraine.
People with outstanding or unexpunged convictions can be mobilised, according to a decree signed by President Vladimir Putin on Friday.
Those convicted of sexual offences against minors, terrorism, hostage-taking and "illegal handling of nuclear materials", among others, are exempt, state media reported.
Mr Putin also said volunteer units have been created in a move to boost numbers after thousands fled the country following a call-up in September.
Nearly 200,00 people are said to have fled Russia, mainly to neighbouring Kazakhstan and Georgia, after a partial mobilisation was introduced, following Moscow's annexation of four Ukrainian regions.
Only 49,000 of the more than 300,000 drafted are in active combat, Mr Putin claimed on Friday, saying the majority are in training.
Soldiers sent to the front, however, have said they received little to no training and have been asked to buy their own equipment.
Some Russian media have reported a two-month waitlist for bulletproof vests, which have "skyrocketed" in price as conscripts scramble to secure their own gear.
Despite its large army, Russia has failed to make significant gains in its invasion of Ukraine.
Its forces are retreating from the annexed region of Kherson, western officials have said, with soldiers "critically low" on ammunition and low on morale.
Moscow is also recruiting US-trained Afghan elite forces for a foreign legion, commanders have told The Associated Press.
It wants to attract thousands of former elite commandos with offers of monthly salaries and promises of safe haven against a near-certain death under the Taliban at home.
The US has said Iran sent trainers to Russian-occupied areas of Ukraine to assist in deploying Iranian missiles on Kyiv.
