Can any one tell me what Focus effects do and how they work. I se them mentioned sometimes with items and also connected with pets. Whats all that about then? Any advice gratefully received
They enhance your spells. Spell haste will make you spells cast slightly faster. Mana preservation will make your spells use less mana. As for pets the focus effect with make the pet a little better (more damage, hp, ac, etc).
Under..er next to each focus what it enhances is listed. As the description will explain, not every focus is viable for each class. Like most would not think that greater healing is a beneficial one for necros, but it is.