The series is composed by three games:
-) Druid 2 - Enlightenment
-) Druid 3 - Warlock the avenger
The plot is remarkably similar for all the three games: the evil Acamantor tries to take control of the world of Belorn with hordes of minions and the Druid Hasrinaxx (controlled by the player) must use the powers of the elements and the spells he knows to journey through several areas of the world blasting the ever-respawning evil minions and replenishing the ingredients for his spells, trying to finally banish Acamantor.
The gameplay of the third title is almost identical to the first one: the landscapes to cross and the minions to face are totally new, but the spells and weapons available to the player are exactly the same. The levels are also sequential in both.
The second title has many more spells available and also a non-linear approach (you have to complete certain tasks to enter the final area, but the order is up to you).