In honour of 40k's 25th Birthday this year, I'm working at an ongoing series called "The Tyranid Archive," which is meant to be a historical look back on where Tyranids came from and how far they've come. Here's our next installment.
3rd Generation (2001)
(Also known as the Birth of Mutable Genus or What Is The Least Number Of Genuses I Can Get Into An Army, We Can Get Them For You Cheap, and Screw This Grinfex: Where's My Plastic Carnifex?)
The third edition codex brought with it a whole world of Tyranid evolutions that we still enjoy to this day. It created Scything Talons and Rending Claws where before there were just Random Slashy Things. The strength of ranged weaponry went from being absolute as defined by gun to being variable as defined by the bearer's strength (Venom Cannons, for example, fired at the strength of the creature carrying them +2, and a devourer on a carnifex was Str 8!). We were introduced to the importance of Synapse and the requisite consequences of Instinctive Behaviour. It was the birth of the Tyranid Monstrous Creature, with its ability to ignore armour and roll 2D6 penetration, and it was the first time Tyrants ever got wings. Genestealers, with their armour-munching rending claws, became the bane of many folks' existence. However, you were lucky if your genestealers ever made it to combat because the newly-introduced, Tyranid-specific "shoot the big ones" (no joke; that was actually the name of it) rule meant that our opponents could ignore standard rules for target priority/screening and fire on any Tyranid unit they liked.
The codex was set up in a similar fashion to others of the era, with a complete list of Tyranid creatures at front of the book, allowing a few options per squad, and you could build a full army from that list.
But then there was this mad, secondary list at the back of the book that fell under the heading of "Mutable Genus List," and it detailed the various "Mutable Genus" species of Tyranid (Gaunts, Warriors, Rippers, Carnifexes, and Tyrants).
