Dr. Alonzo Richter first published the Richter Scale of Cultures in 2203. Since then it has become the Federation's most important tool for determining at which point in a civilization's development the Prime Directive no longer need apply. Most first contact missions take place when a society reaches a classification of G. Exceptions include planets that do not wish contact, planets that were already contacted by non-federation agencies, and planets that were contacted before the Richter Scale was devised.
 
The classifications in The Richter Scale of Cultures is not necessarily an in-order listing of power per se, although that usually is the case. Attributes like planetary government and non-aggressiveness are factored in.
 
Ratings higher than our own (N) are extremely speculative since more advanced beings and races are not always forthcoming about themselves and we usually have no way of covertly or openly studying them.
 

 
AAA
No Known Intelligent Indigenous Life-Forms
  • Ceti Alpha 5, Manark 4, Melnos 4, Miridian 4, Nelvana 3, Nervala 5, Ohniaka 3, Omicron Ceti 3, Quazulu 8, Regulus 5, Septimus Minor, Sherman's Planet, Tethys 3, Titus 4,Vilmor 2, Zayra 4
AA
Prehistoric Age (No Tools)
  • Alpha Carinae 2, Alpha Majoris 1, Bardakia, Berengaria 7, Dimorus 4, El-Adrel 4, No'Mat, Ruah 4, Surata 4
AS
Primitive Space Dwelling
  • Alpha Omicron System (Junior), Giant Amoeba, Nitrium Parasites from the Pelloris Asteroid Belt near Tessen 3, Ordek Nebula (Wogneers)
A
Stone Age
  • Altair 3, Gamma Trianguli 6 (Vaal), Hanson's Planet
AR
Primitive ( RESTRICTED - No contact permitted)
  • Tarchannen 3, Tarella, Taurus 2
B-
Agricultural Age
  • Malkus 9, Miramanee's Planet, Rousseau 5
B
Metal Age
  • Apella, Capella 4 , Sigma Draconis 6, Galvin 5, Malurians (before demise), Zeta Bootis 3 (Neural)
C-
Scientific Intelligence With No Tools
  • Janus 6, Tyrellia
C
Scientific Age
  • Barkon 4, Fendaus 5, Mintaka 3
D-
Pre-Industrialization
  • M-113 (before demise), Omega 4, Organian Society's Outward Appearance, Sigma Draconis 3
D
Steam Age
  • Argo, Brax, Canopus 2, Omicron 4, Rigel 7, Tartarus 5
D+
Electric Age
  • Landris 3, Minara 2 (before relocation), Mintonia, Rubicun 3 (Edo)
E-
Liquid Fuels Age
  • Kraus 4, Loren 3, Stakoron 2, Suvin 4
E
Atomic Age
  • Barzans, Deneb 4 (Bandi), Beta 3, Mordan 4, Sigma Iotia 2
F
Space Age
  • Alpha Carinae 5, Altec, Argelius 2, Balosnee 6, Brekka, Kea 4, Penthara 4, Sarona 7, Straleb, Talin 4, Theta 7, Turkana 4
F+
Conscientious Space Age
  • Halkans, Marejaretus 6, Norpin Colony, Tagus 3, Thalos 7, Tohvon 3
G
Fusion Age
  • Antica (Beta Renna System), Deneb 2, Drema 4, Gamma Vertis 4, Jaros 2, Ligon 2, Manu 3, Minos Corva, Nahmi 4, Niau, Ophiucus 3, Regula, Selay (Beta Renna System), Sigma Draconis 4, Solais 5, Thelka 4, Ventax 2, Xelata
H
Planet Age
  • 892 4 (Magna Roma) , Angel One, Bre'el 4, Ekos, Elas, Kataan, Kenda 2, Krios, Malcor 3, Ornara, Phylos 2, Quadra Sigma 3, Relva 7, Rochani 3, Troyius, Vault Minor, Zeon
I
Star Age
  • Algolia, Altair 6, Antide 3, Barolia, Breen, Chalna, Corvan 2, Gamelan 5, Largo 5, Ligos 7, Miradorns , Pakleds, Pelleus 5, Pentaurus 5, Regulus 2, Rura Penthe
J
Expansion Age
  • Alcyones, Berellians, Brakas 5, Gault, Lysia, Mudor 5, Nausicaa, Ogus 2, Otar 2, Qualor 2, Sothis 3 (Sataarans), Shiralea 6, Styris 4, Tarsas 3, Tormen 5, Tyrus 7A, Valeria, Zibalia
K
Introversion Age
  • Acamar 3, Alpha Proxima 2, Beta Antares 4, Coridan, Epsilon Hydra 7, Gamaris 5, Mizar 2, Narendra 3, Nimbus 3, Peliar Zel, Persephone 5, Setlik 3, Vadris 3, Xanthras 3, Zytchin 3
K+
Enlightenment Age
  • 15 Lyncis 2 (Cait), Bajor , Gaspar 7, Hoek 4, Hurkos 3, Kurl (before demise), Mariah 4, Mataline 2, Meles 2, Memory Alpha, Pacifica, Parliment, Risa, Sauria, Sirius 9, Valo 2, Valo 3, Wrigley's Pleasure Planet, Zeta Alpha 2
L
Power Age
  • Angosia 3, Beltane 9, Benzar, Devidia 2, Dopteria, Eminiar 7 , Epsilon Canaris 3, Lenaria, Mantilles, Mariposa, Melina 2, Midos 5, Milika 3, Morikin 7, Oceanus 4, Promelians, Rakhar, Rigel 2, Rutia 4, Tagra 4, Tarsus 4, Vendikar, Zadar 4
M
Ion Age
  • Alpha Cygnus 9, Ardana, Bilana 3, Catualla, Canopus 3, Dachlyds, Daran 5, Delos 4, Deneb 5, Gonal 4, Hurada 3, Kaelon 2, Kaldra 4, Krisa, Kostalain, Lemma 2, Makus 3, Menthars(before demise), Merak 2, Nehru Colony, Zaldor
MR
Ion Age ( RESTRICTED - No contact permitted)
  • Kavis Alpha 4 (Evolved Nanites), Ktaria, Mab-Bu 6 A, Moab 4, Rigel 8 (Orion), Sarthong 5, Tanuga 4, Velara 3
N-
Pre-Technocracy Age
  • Aurelia , Axanar, Beta Lankal, Beta Thoridar, Beta 6, Beth Delta 1, Bolarus 9, Cardassia , Edo (Edoans), Ferenginar, Kora 2, Malaya 4, Talaria, Tau Ceti 3 (Kaferia), Tiburon
N
Technocracy Age
  • 61 Cygni 5 (Tellar) , Alpha Centauri, Alpha 3, Andor (Epsilon Indii 8) , Arvada 3, Babel, Benecia, Bersallis 3, Beta Agni 2, Boreth, Borka 6, Cygnet 12, Deneva, Earth , Gideon, Gornar , Haven, Klaestron 4, Marcos 12, Minos Korva, Q'onos (Klinzhai), Rigel 4, Rigel 5
NR
Technocracy Age ( RESTRICTED - No contact permitted)
  • Minos, Platonius, Remus, Romulus , Scalos, Sheliak Corporate, Tau Cygna 5, Tholia, Tilonus 4
N+
Civil Technocracy Age
  • Betazed , Caldonia, Chandra 5, Danula 2, Delb 2, Delta 4, Efrosia, El-Aurians, Icor 9, New Fabrina, Ramatis 3, Tamaria , Trill , Ullians, Vulcan , Yonada, Zakdor
N+PR
Civil Technocracy Age ( RESTRICTED - No physical contact permitted)
  • Gagarin 4, Torona 4
NS
Space Dwelling Civil Age
  • Beta Renna Cloud, Beta 12-A Entity, Calamarain, Crystaline Entity, Dikironium Cloud Entity, FGC-47 Entities, Gamma Canaris Entity (Companion), Space Jellyfish
O
Techno-Power Age
  • Bynaus, Cerebus 2, Legara 4, Medusa, Mudd, Sarpeidon (before demise), Vorgons (from the 27th century)
P
Super Techno-Power Age
  • Amusement Park Planet, Borg Collective , Dyson Sphere Builders, Iconia (before demise), Old Ones of Exo 3 (before demise), Rubicun 3 (Edo God), Sargon's Planet (before demise), Triacus (Epsilon Indii 4, before demise)
PS
Space Dwelling Super Techno-Power Age
  • Gomtuu (Tin Man), V'ger, "Whale" Probe
Q
Cloaking Age
  • Aldea
R
Exploratory Age
  • Cytherians, Tkon Empire (before demise), Makers (of androids on planet Mudd), Vians
S
Transformation Age
  • Antos 4, Daled 4
T
Illusory Age
  • Melkotia, Prakal 2
TR
Illusory Age ( RESTRICTED - No contact permitted)
  • Talos 4
U
Dimensional Age
  • Guardian of Forever, Tau Alpha C (Traveler), Triskelion (Providers)
V
Altering Age
  • Excalbia, Trelane of Gothos, Kelvans, Pollux 5 (Apollo - before demise), Pyris 7 beings (Korob & Sylvia)
W
Galactic Age
  • Bajoran Wormhole Entities (Prophets), Dowds, Kalandans, Metrons, Preservers
WR
Galactic ( RESTRICTED - No Contact Permitted)
  • Vagra 2 (Armus), Lactra 7
X-
Pre-Non-corporeal
  • Discarders of Armus, Zalkonians
X
Non-corporeal Age
  • Organians, Thasians, Koinonians, Zetarians
XX
Nigh Omnipotence Age
  • The Q Continuum