Level 5 planet

A Level 5 planet, also called a level 5 civilisation, was a designation used in reference to relatively primitive planets not yet fully integrated into galactic civilisation, and as such were protected by various Galactic Laws. (TV: Smith and Jones, Partners in Crime, The Eleventh Hour) The designation was derived from socioenergetics. (TV: State of Decay)

Romana II stated that level 5 planets were notoriously bad at long-term planning, in regards to ecology. (AUDIO: Legacy of Death) Although they were protected by organisations such as the Shadow Proclamation, it was possible for level 5 planets to be taken over legally. (PROSE: Nothing O'Clock)

While a level 2 planet in the 1940s, (PROSE: Ghosts of India) Earth became a level 5 civilisation in 1957 after the launch of Sputnik, (PROSE: Time Traveller's Diary) remaining at that status through 1979, (TV: City of Death) 1986, (TV: Twice Upon a Time) 2008, (TV: Voyage of the Damned, Revenge of the Slitheen, The Eleventh Hour) 2009, (TV: Partners in Crime) 2016, (PROSE: What She Does Next Will Astound You) 2020 (PROSE: At Childhood's End), and into 2040, (AUDIO: Phantoms of the Deep) although Romana I once referred to Earth in 2011 as having a level 4 civilisation. (AUDIO: Ferril's Folly)

Aoris was a level 5 planet in Era 24 of its history. (AUDIO: The Paradox Planet)

By Galatic Law it is illegal to use a Level 5 planet for breeding; though this didn't stop the Adipose and Sontarans from attempting it. (TV: Partners in Crime, The Sontaran Stratagem) Likewise, it was also punishable for attempting to destroy a Level 5 Planet to kill a single criminal. The Atraxi are lucky the Doctor only scolded them. (TV: The Eleventh Hour)