MEQ
MEQ is a slang term among Warhammer 40,000 players that stands for (Space) Marine Equivalent. It refers to any unit with a stat-line similar to that of a Space Marine (WS4 BS4 S4 T4 W1 I4 A1 Ld8 Sv3+). Usually the important part is how easy or hard they are to kill (Toughness, Wounds and armor save). A model with T4 W1 Sv3+ is a "pure" MEQ.
Strong examples:
- Space Marines in Power Armour
- Chaos Space Marines in Power Armour (with the exception of Plague Marines, who have an extra point of Toughness)
Loose examples:
- Tau Crisis Battlesuits (though they have two wounds each, altering the dynamic to grant S8+ extra utility for inflicting Instant Death)
- Necron Warriors and Immortals previously (although they no longer count count due to having 4+ armor saves instead of 3+, since the 5th edition Necron Codex, but Reanimation Protocols (WBB v2.0!) increases their survivability)
TEQ
TEQ, short for Terminator Equivalent, refers to a unit with a statline similar to Space Marine Terminators. Usually, this means a 2+ armor save and some kind of Invulnerable save (on top of the regular MEQ profile). Sometimes, instead of an improved armor save and invulnerable save the extra resilience comes from increased Toughness or Wounds.
Strong examples:
- Space Marine Terminators
- Chaos Terminators (which are basically Terminators with spikes, some flayed skin and the kind of bad attitude that you have if you have not had your regular cup of morning coffee)
- Grey Knight Paladins (which are actually just super-Terminators)
- Dark Angels Deathwing Terminators and Deathwing Knights (although, again, these are just super-Terminators)
Loose examples:
- Ork Meganobz (though they have two wounds each, altering the dynamic to grant S8+ extra utility for inflicting Instant Death. In addition, they don't have inv. saves.)
- Chaos Space Marine Mutilators and Obliterators (same multi-wound factor favoring S8+ weaponry).
- Tau Broadside Battlesuits.
- Necron Lychguard and Triarch Praetorians (with Toughness 5, 3+ inv. save and reanimation protocols on top of that? Bruh.).
- Tyranid Warriors, Shrikes, Raveners, Tyrant Guard and Hive Guard.
- Imperial Guard Ogryns and Bullgryns.
- Eldar Wraithguard and Wraithblades.
- Dark Eldar Grotesques.
GEQ
GEQ, short for Guard Equivalent, refers to units with a statline similar to Guardsmen. Usually, this means T3 W1 Sv5+, although the important part is usually that they are more vulnerable than Space Marines. T3 Sv4+ or T4 Sv5+ can loosely fit into this category.
Examples:
- Imperial Guard (pretty much every type).
- Eldar Guardians, Dire Avengers, Howling Banshees, Swooping Hawks and Harlequins.
- Dark Eldar Kabalite Warriors, Wychs, Mandrakes, Wracks, Scourges and Hellions (although they can get FnP, among other fun things.).
- Tau Fire Warriors and Kroot.
- Tyranid Gaunts and Gargoyles.
- Chaos Cultists.
- Chaos Daemons such as Bloodletters, Pink Horrors, Daemonettes, Chaos Furies and Seekers of Slaanesh.
- Orks ALL OF THE ORKS W/OUT 'EAVY ARMOUR.
Knight
Although not a widely-accepted term, Knight has been used by some to refer to the large models being released by Games Workshop. Usually, these have a high Toughness (at least 6, and often more), a large number of Wounds (at least three and sometimes up to six), a 3+ or 2+ save, and an invulnerable save (or some way to get them). They also seem have to have high mobility, usually in the form of jetpacks or teleporters or similar. These models are also very large, which means it's hard to hide them, and most are Monstrous Creatures.
The term "Knight" is both a reference to the high incidence of the term "knight" in their names, and the Knight Titans of Epic 40,000.
Examples:
- Grey Knights Dreadknight
- Tau XV-104 Riptide
- Eldar Wraithknight
- Imperial Knight
- Ork Gorkanaut/Morkanaut
The Other Stuff
Of course, a lot of stuff doesn't fit very well into any of the above categories. For instance, Space Marine Centurions have multiple wounds, extra Toughness, as well as 2+ saves and larger bases, so they don't really fit as MEQ or Knight. Similarly, the entirety of Sisters of Battle is somewhere between GEQ and MEQ; they all have Toughness 3, but they also have 3+ saves and a 6+ invulnerable save. The same applies to Ork Boyz who are Toughness 4 and have a 6+ save. Several Tyranid organisms have 2 wounds but a 4+ save or worse and no Toughness increase meaning that they are between the resilience of a TEQ and a MEQ.