The game Star Trek: Armada has four kinds of ships, that can be considered a caster:
These ships are generally slowly moving, have low shield energy and very limited firepower. However, their four special_weapons make them very dangerous/useful, nevertheless.
They are rather expensive in comparison to other ships and are especially good at supplementing other units or negating an opponent's offensive capabilities. As such they require often more Micro Management than other units.
Depending on the used Techtree the ship may not be available at all, may require research to be done for each special weapon or may come fully equipped, once produced.