I once heard of some kind of equip systems, something like what would be in Crescent Dyne...

What I mean is a system with wich you apply armor/weapons/items on your hero, but I wonder waht kind of vHP it takes to detect what armor the player has and how does it reduces dammage, same for weapons.
I do not need complete trigger explaination, i am not a mapping begginer. I only need some pointing, because i really wonder how to do it.

If you could enlighten me, i'd be very happy

Using a normal vHP system with the good old burrowed unit recycled under your hero and a death detection, it's very easy to come up with varying the damage dealt since, at the base, the damage dealt without any factor is set by you... you can do the same by adding different variables in:
A normal map w/o complexity would, for example, go for a 7 damage/hit.
If you go for a system like CD would have, you would do something like this:

Triggers check what armor you got to reduce the right number of DC on the amount of damage dealt.
Plus, depending on the enemy that killed that unit, I know it's weapon type, which also affects differently on each armor: an other variable to take in count, reducing the damage dealt or raising it.

And it would keep going like that... for a long looong time XD

Did you mean having a burrowed unit constantly moved under the said hero that is attacked to make the palyer lose hp?
If so, I could think of a way to use armor... but i don't see how to extend it to over 5-6 armor types.

In my opinion, it's best to set up your map's functions and then adapt armor/weapons/items to it. There are countless ways to use Armor and weapons systems. The most exact, but time consuming usually use vHP, but there are also ways to do Equipment without vHP, you just have to be creative.

Don't forget that as the maker of the map, you get to decide what defines armor, what defines a new weapon. What your items do ect. So be creative and find something that works for you. You have things such as unit HP%, Unit base armor/armor upgrades, attack upgrades, vHP and more to use, so use it. But first of all, definitely find out what kind of systems your map will use before making an equipment system that works best for the given map.

Armor types? What do you mean? Something like big/medium/small units?
Or is it enough to have different armor values? Then it's simply a matter of how many units you stack under your hero. Something like that:
1 defiler 10hp: Leather cap (10)
1 ling 25hp: Rags (25)
2 lings 25hp: Leather armor (50)
2 lings 25hp + 1 defiler 10hp: Studded Leather armor (60)
2 lings 25hp + 1 lurker 5hp: Spiked Leather armor (55)
That way you can easily create hundreds of items using prefixes:
Studded = add 1 defiler; Spiked = add 1 lurker

Usually you should ensure that always only 1 unit is vincible at any time. However you can simulate a % hp drain by attacking with splash and making all units vincible for that time.

If your hero is a Protoss unit, you could use a Set Shields system.

For example,
if nothing is equipped, constantly Set Shields to 0%.
if Leather Armor is equipped, constantly Set Shields to 25%.
if Chain Mail is equipped, constantly Set Shields to 75%.

@ NudeRaider: Thats exactly what I needed, thank you. couldn't think of a way to do it but now i guess it is going to be okay.

@ ForTheSwarm: I may use protoss units, so it might be helpful too, thanks.

One last thing, how should I do it? When the player loses all his armor pieces he is dead or he loses a set ammount of hp?
Edit: I mean, what should I do? SHould it be that when you lose all pieces of armor, then you are vulnerable? Or when you lose all pieces of armor you lose 1 hp and then armor is recreated?

The point of vHP is that the units are your hitpoints - as the name suggests. So when all units under you are dead you die.
However the methods you describe are also possible. Pick whatever you want.

You could make everything virtual. When player 2 casts a spell, it's player 1's MAGIC DEFENSE is subtracted from the MAGIC POWER of the spell Subtracting (Magic power - Magic defense) counts of "HP" for player 1. Then set it up so that when a player reaches 0 counts of "HP" their unit dies, and optionally you could set HP% accordingly for that unit. Of course, different pieces of armor would set the player's MAGIC DEFENSE count differently, just like you could have different weapons or items increase the player's MAGIC POWER or ATTACK POWER counts.

The only downside of this is:

1:It's a lot of Effin work.
2:Players wont be able to attack normally with their unit's natural weapon.

Well nuderaider's idea fits greatly with what i want to do, but is there a way for the player to be able to see his HP? Are the burrowed units controled by the said player?

As long as you disable burrow tech there should be no problem with it.
You could use the leaderboard to show the hp. Keep track of the units under your hero and subtract hp if one dies to get a fairly accurate display. Doesn't count damaged hp parts, obviously.

Alright, so by creating the burrowed units for a computer and giving them to the player, I might have a system that lets you see your HP. Maybe i will not need the leaderboard... well I guess thats all I needed. I ma making the rockzorz RPG for the Yearly RPG contest, last stand...