Dream is a rune word used in Helms and Shields. Requires an extremely rare Rune in the form of JAH. All characters can wear a dream runeword helm or shield, but paladins benefit the most because they have synergistic abilities with the holy shock aura provided by dreams.
Technically, any character can equip a Helm/Shield dream runeword. But Paladins benefit the most, because only they could level up Holy Shock’s twin synergistic Abilities: Resist Lightning and Salvation. By having high levels in each of these two Skills, they can really increase the damage of the Holy Shock Aura provided by Sleep.
+20-30% faster hit recovery (varies)
When your character catches it, there are a few frames of animation. If your opponent hits you for 1/12 of your hit points or more, you also risk being stunned. Faster Hit Recovery helps your character recover from being hit by his enemies; the more you have, the faster you can recover from hits and dish out your own damage.
+10TB of vitality
It’s not a huge amount by any means, but it’s still useful for having those extra hit points in a fight.
Increases Max Life by 5% (Helms Only)
+50 health (shields only)
Both mods increase health, depending on whether you form the dream runeword on a helm or a shield. Obviously, if you have more than 1000 health, it would be more advantageous to create Dream in a Helm. However, it will very much depend on whether you have another Helm/Shield that provides better stats and mods to your character.
All Resistances +5-20 (varies)
Dream also gives players a small boost to All Resistances.
Summary:
Dream Runeword appeals to paladins who already have max levels in both Resist Lightning and Salvation, and want to make use of Holy Shock Aura Dream grants. Other classes or builds will find that the small boost to Life and All Resistances does not justify the high cost of Dream.
Note: As of patch 1.13, equipping a helm and shield with the dream runeword will no longer stack the holy shock aura at level 30.