The following is a situation me and a friend of mine often fall into.

I have on the quest side a [whi]Dwarf Ranger[/whi]. On the battlefield I have a unit of [whi]Defender of the Hold[/whi] and a [whi]Grudge Thrower[/whi].

He got on his battlefield a unit of [whi]Bloodsworn[/whi] with 2 damage counters on it.

The question is: if I sacrifice the [whi]Defender of the Hold[/whi] using the ability of the [whi]Grudge Thrower[/whi], can I do the damage (for the [whi]Dwarf Ranger[/whi]'s ability) to the [whi]Bloodsworn[/whi] and kill it, or it gets healed prior of this due to the fact that my unit goes in the discard pile (and it takes one damage afterward)?

He gets healed before dwarf ranger will shoot him.
This is because his "Forced" triggered
any time when a unit enters discard pile.
And Ranger's "Forced" is worded: after one of...

It is the same case for the Dwarf Rangers.

The problem is wich one take action before the other...

Player 1 action: Sacrifice the dwarf with Grudgethrower
Player 2 action: Heal the Bloodsworn
Player 1 action: Deal 1 damage with Dwarf Ranger
Player 2 action: nothing

If the stack is like that, the Bloodsworn should die before healing... since it resolves backwards...

Exactly... But if the stack resolves like this:
Player 1 action: Sacrifice the dwarf with Grudgethrower
Player 1 action: Deal 1 damage with Dwarf Ranger
Player 2 action: Heal the Bloodsworn

The Bloodsworn gets healed...
Which of the 2?

sry my bad. All abilities are Forced, so
check out my corrected answer.

Got it. Thanks Justice!

Justice wrote:He gets healed before dwarf ranger will shoot him.
This is because his "Forced" triggered
any time when a unit enters discard pile.
And Ranger's "Forced" is worded: after one of...

I assume the original answer said something about the stack, since all the replies reference it. There is no stack for forced actions, in case that was unclear to anyone.

However, I think your answer is incorrect. Some time back, they errata'ed all cards that say "after" to instead be "when", otherwise it was a vague trigger, since you could technically trigger the effect long after the event occurred (All instances of “After your turn begins” should read “At the beginning of your turn.” All instances of “after” in card text boxes should read “when.”). This means Dwarf Ranger triggers at the same time as Bloodsworn. Since its a tie, the active player gets to resolve his effects first (FAQ v1.1 and the Rules Summary here). In this example, that would be the Dwarf player, so the Ranger would kill the Bloodsworn before his effect is resolved.

Interesting point...

Just checked FAQ.
Thanks Entropy, i've missed that "when" and "after" thing.

So basically when there are 2 or more "Forced abilities" in stack, active player decide the resolution... as far i've intended.

Not quite. If the forced effects belong to different players, the active player resolves all his forced effects in the order of his choosing, then the other player(s) do the same, in turn order. The active player can't choose to resolve his opponent's forced first, for example.

So once a player resolves an effect this doesn't go to stack but resolves immediately right?
Otherwise I would have resolved my dmg on the Bloodsworn but the oppenent would then heal him retroactively.

Yes, there is no stack for forced, constant, or triggered effects. Only actions.