Strains are variations of the alien you play as, changing up their play style to something either slightly or completely different to the normal alien. This allows you to change your play style to experiment with.
You can pick your strain from the get go if your caste has any strains available to them. When you evolve you will lose the strain you previously picked. Each Xeno can purchase one Strain available to their caste and they are permanent.
Under the Alien tab you can buy strains for yourself with the Purchase Strains verb.
Strains
Each Strain is permanent, will alter how you'll play the caste and can not be reverted.
Trade the ability to build resin structures for an ability to plant resin fruit on weeds that can be eaten by other aliens to regain health, gain an overshield, or decrease ability cooldowns, as well as an ability to resin surge (20 sec cool down), skipping 5 seconds in plant maturity, increasing a basic structure's health (+6000), or create a 3x3 of weak sticky resin or temporary wall (Wall is very weak).
You loose all of your abilities and you forfeit a chunk of your health and damage in exchange for a large amount of armor, a little bit of movement speed, increased attack and brand new abilities that make you an assassin. Rush on your opponent to disorient them and Flurry to unleash a forward cleave that can hit and slow three marines and heal you for every marine you hit. Use your special AoE Tail Jab to knock marines away, doing more damage with direct hits and even more damage and a stun if they smack into walls. Finally, execute unconscious marines with a headbite that bypasses armor and heals you for a grand amount of health.
Lose your ability to pounce, long range sight, some speed and bone spur. In exchange, you get increased health to 345 HP, 15 base armor, and get a volatile acid gland that passively fills with acid. Gain an ability called For the Hive that when activated, will prime yourself to detonate in a large explosion of acid, depending on how much acid is stored.
Trade the ability to tail sweep and 5 slash damage for the ability to use headbutt while your crest is lowered. Additionally, your headbutt does more damage, gains 1 tile extra range and you're able to move slowly while fortified.
Lose the ability to make thick resin, acid items and lose some plasma reserves. In exchange, you gain the ability to see farther as well as the ability to remotely create resin structures.
Trade the ability to carry and throw facehuggers as well as the ability to make traps for the ability to generate an egg every 30 seconds, additionally gain stronger pheromones.
Trade the ability to spit/spray acid and a hefty chunk of your armor for greatly increased speed and three new abilities: Impale, Dodge, and Tail trip. Dodge is an active ability that greatly buffs your speed and allows you to phase past tall hosts. Tail trip is also an active ability that trips your target, causing a daze and if they are tagged, a short knockdown. Impale deals direct damage and if they've been tagged, stab them twice.
Trade most of your speed and acid spit to become a nigh-indestructible bulwark of the Queen. Your slashes deal increased damage to prone targets, and you gain a stomp that knocks over opponents in front of you as well as a ability that buffs your next slash and one that knocks your opponents back.
Trade your corrosive acid and your dash for an internal hitpoint pool. The pool is filled by your acid spit and slashes which can be spent on abilities that aid your allies.
Trade your corrosive acid to get a shield that perfectly blocks one attack, which recharges out of combat. Gain the ability to use pierce that penetrates through opponents, also instantly recharging your shield if you hit 2 targets. You also gain cleave, which has two states: Root, which'll immobilise a target; Fling, which'll fling a target away from you
Trade your long range bombarding and long distance view range buffer for unavoidable acid mines, rooting traps to slow down your enemies and short range acid shotgun.
Trade your base abilities for increased health, mobility and new abilities that turn you into a immobile death machine. Build up your rage levels through slashes and unleash terror upon thy foe with your new abilities. Apprehend allows you to close the distance between you and your target. Clothesline allows you to deal moderate damage to a target next to you in exchange for using a level of rage. Annihilate your targets all around you with the new eviscerate ability to rip and tear your enemies guts out.
Trade your base abilities and plasma for a shrapnel based powers. Gain shards of spikes passively or when you get hit. Gain 3 new abilities to replace the old ones. Spike Shield allows you to gain a temporary shield that, when damaged, sprays shards of shrapnel outwards. Fire Spikes allows you to launch spikes in the a desired direction. Spike shed allows you to shed all your spikes, launching them all around you, for a quick boost in speed.