Stack Size determines how many units can be in each army. This guide on How To Increase Stack Size In Spellforce Conquest Of Eo will tell you the multiple ways you can increase your stack size so that you can greatly expand your armies and enter battles with thousands of power instead of just hundreds.
When you first begin the game you are limited to only a select few stack slots in each army. At the beginning your maximum stack size is 4 but you can only actually have three units in the army. This is because there is always a stack slot reserved for a Hero or Apprentice, this is the slot on the army bar marked by the star icon. This is the same for all mages, classes, and spell school combinations.
How To Increase Stack Size In Spellforce Conquest Of Eo
There are multiple ways to increase your stack size. Firstly, you want to upgrade your Tower. When you unlock Allfire you can choose to invest it into three different categories. Mana, Research, and Proficiency. Proficiency turns into Mastery which in turn increases your Tower rank quicker. As you reach milestones in Tower rank, you will unlock new stack slots. You can check the + icon next to your Tower to see what the next level required is to gain more stacks.
My first playthrough of the game was on a Necromancer, so this may not apply to all types, but I’m sure much of it does. Another method of obtaining new stack slot increases is to construct and upgrade certain buildings in your Tower. For example, the Necromancer’s Crypt is a structure you get very early and once you have unlocked Room Extensions, you can add a War Room to it to increase your stack slot size by 1. The Soul Well, which you unlock through Necromancy Grimoire advancement is another building that provides an additional +1 stack size. Another structure that is available to all mages is the Warriors Hall.
If you reach maximum friendship with the city of Audale in Gillyshire, you will unlock the Warriors Hall blueprint. This instantly provides a further +1 to your stack slot once constructed.