The Korea Military Academy will allow cadets to drink, smoke, and date outside the school. It will keep a ban on cadets marrying but permit them to get engaged.
The bans have been in place unchanged since 1952 and are habitually flaunted.
The new rules will allow cadets to drink or smoke so long as they are not engaged in official duties or attending official events outside the school. They can have sexual relationships outside the school unless they cause "social and moral problems," the academy said.
Under the current rules, cadets may only drink in school in exceptional cases that have the blessing of their superiors, and outside school only at family events or parties hosted by senior officers.
The bans were tightened just last August after one cadet raped a female fellow student at the school in May and another solicited sex from a minor in July.
But critics have long said the rules are anachronistic, blaming their tightening for an increase in the number of dropouts from 10 in 2012 to 45 in 2013.
"Cadets abide by the strict rules only when they can be seen but ignore them the moment no one's watching," a senior Army officer said. "The new policy aims to resolve that problem."
The academy will to consult parents and retired officers about the plan on Wednesday before finalizing it.