Tactics are 1 of the 2 major ways you'll enhance your Evotype's capabilities during a run. As you go through Mind Training, you'll eventually be given the option to choose from 1 of the 7 elements available, those being Fire, Ice, Electric, Toxin, Umbra, Light, and Blade. Each element has a Tactic group that correlates to one of the 5 Tactic Slots which determine how you trigger the Tactic's abilities. Tactics are designed to work in tandem with each other and reward players who discover powerful combinations that synergize with your Evotype. Not all Tactics are made evenly however, which leads to some tactics seeming extremely good while others are lackluster.
Tactics will appear in 4 different rarities, Common -> Uncommon -> Rare -> Legendary, with each rarity being an upgraded version that increases the utility of what the Tactic does, such as increasing the damage percentage or duration. These Tactics can be upgraded to the next rarity via a Tactic Ascension found in various places. Additionally, Tactics have 3 stages going from the base tactic, secondary upgrade, and then third upgrade. You can only have one base Tactic on each slot, and you cannot have the same Tactic on two different slots such as Cold Attack and Cold Skill which you can only obtain one of in your run. The secondary upgrades is always a choice between different upgrades to make it unique. Finally the third upgrade only has one option. Once you have have 3 Tactics in one Tactic Slot, the only way to continue to upgrade that slot is with Tactic Ascensions and Double Tactics.
Double Tactics are a combination of 2 Tactics from different Tactic Trees and/or Elements. These Tactics combine the attributes of the 2 Tactics to make a powerful tactic that goes in the 4th slot in your Tactic Slots. These Tactics require you to plan ahead by viewing the Tactics Codex and look at the Tactic Tree to see what Doubles are possible with that Tactic. In order to obtain a Double, you'll need to obtain the 3 Tactics from the main Tactic and the base tactic from the other required Tactic. Only then will the Double appear in the respective element.
When passing down Tactics via a saved Evotype, any base tactic will be automatically equipped when you start a new run. Secondary/Third/Double Tactics will not be equipped until you obtain the necessary base Tactic. Double Tactics when being passed down have the unique property of often only needing the base Tactic associated with it, allowing you to get a Double that only requires 1 Tactic Slot be filled and creating a new combination in the now open slot.
Once you've filled in the first 5 base slots, you'll only see Tactics of those Tactic's respective element, allowing you to only focus on upgrades at that point. Inheriting certain elements allows you to manipulate how likely you are to see a certain element without sacrificing any Mind Crystal slots. When attempting to get the "1+1>2" achievement, this significantly helps steer your 5 Doubles in the right direction.
