Casters cannot be deliberately Popped. Instead, every time the Side Pops a Warlord, it has a chance to become a Caster instead. Presumably, the chance to Pop a Caster lowers drasticly, the more Casters the Side already has.
Use of Magic
Every caster belongs to a school of Magic (e.g. Thinkamancy or Croakamancy) and can cast spells from that school. Casting spells uses a Caster's JuiceErf-b1-p104 so there is a limit on the amount of magic a Caster can perform during one turn Erf-b1-p090.
Casters are also able to use Scrolls to cast spells; from their own schoolErf-b1-p125, to conserve Juice, or to cast spells they don't know, such as from other schools of Magic (apparently with varying efficiency)Erf-b1-p006Erf-b1-p013.
However, they almost never do so since they are too rare and valuable to risk. Moreover, they do not have the Leadership ability and do not grant a Leadership bonus to units under their direct command. Casters can grant a special bonus to particular units, presumably limited to those directly tied to their magical specialty: known examples are golems led by a Dirtamancer and uncroaked led by a Croakamancer.Erf-b1-p084a
Casters are extremely rare, so there must be something restricts the supply of casters. This effect is sufficient that each side has only a few casters.
Some possibilities on how casters' numbers might be restricted:
- Popping a humanoid unit has a small chance of popping a caster
- Casters are extremely expensive
- Casters have a high upkeep cost
- Casters cannot be popped, only hired from the Magic Kingdom
- Popping a caster gives a random caster that might not be of the type you need
- There is a limit on the number of casters in the world (could be based on each type)
- The odds of a caster popping decreases as the number of casters in the world increases
- There is a hard limit on the number of casters in the world
- The cost of popping a caster increases as there are more casters
- A side can only pop a caster if it has two or fewer already.
- Every turn a caster has a chance to randomly pop in a city
If the number of casters per side was limited to around three on average, then sides would have to think carefully about which types of caster were the most important. It would also be self balancing.
Casters, Sides, and the Magic Kingdom
The Magic Kingdom is a special location that only casters can enter. Casters from active sides can enter and exit the Magic Kingdom via portals. However, it is not clear that all casters in the Magic Kingdom belong to sides on Erfworld. The number of casters in the Magic Kingdom may, at any given time, outnumber those on Erfworld. This also begs the question, do popped casters occur naturally in Erfworld, or are they pulled from the Magic Kingdom? Is the Magic Kingdom effectively a side of its own, or just a neutral ground for casters? Can a Ruler give orders to a caster in the Magic Kingdom?