I couldn't find much on this but i did find a bit here
Reduced:
Damage can be reduced in Diablo III by various character skills and
traits, as well as by equipment bonuses.
Reduction differs from resistance in that it reduces damage by a set amount, rather than
lowering the damage taken by a percentage. Nothing is yet known about
Diablo III's order of operations in damage calculations, so it's not
known how the game will process damage.
In Diablo II, reduce and absorb bonuses were calculated 'after resistance lowered the incoming
damage, making them very valuable. For instance, a 100 point fire
damage attack would drop to 25 points if a character had 75% fire
resistance, and then that 25 points of damage was further lowered by
reduction or absorption modifiers.
Blocked:
Blocking is a property granted by the use of a shield, or by other
items or weapons, in rare situations.
Blocking works very differently in Diablo III than in past games in the series. In D3, blocking is
basically an item based form of absorb, reducing the physical damage
of attacks by a set amount, one based on the shield being used and
potentially modified by skills or traits. This has the effect of
making shields much less protective than they were in Diablo II, when
any character could eliminate up to 75% of all incoming physical
damage with the use of a shield.
A successful block in Diablo III is calculated much as it was in Diablo II, with the character's dexterity
and equipment checked against the attack rating of the enemy.
Presumably blocking will not work while running in Diablo III, though
this is not confirmed.
Absorbe:
Damage can be absorbed in Diablo III equipment bonuses. There may also
be character skills and traits that provide absorption, but none are
yet known.
Absorb differs from resistance in that it reduces damage by
a set amount, rather than lowering the damage taken by a percentage.
Nothing is yet known about Diablo III's order of operations in damage
calculations, so it's not known how the game will process damage.
In Diablo II, reduce and absorb bonuses were calculated 'after resistance
lowered the incoming damage, making them very valuable. For instance,
a 100 point fire damage attack would drop to 25 points if a character
had 75% fire resistance, and then that 25 points of damage was further
lowered by reduction or absorption modifiers. Absorb was even better
than the numbers suggested, since points absorbed were actually added
back as healing. Thus a character with high resistance and absorption
could actually gain hit points from an attack of that element.
Then you also have the ability to dodge
Dodge chance is a new character property in Diablo III. It's something
all characters have inherently, like resistances, defense, critical
hit, Attack Rating, etc. Dodge chance can be boosted with stats,
equipment, traits, and skills.