hey if u enchant a skill and we take for exsample Entagle pw slow skill.

dos it just works on a % chance base or on M atk (int) base?

and is this with all type of chance skills freezing strike (dunno if i got the correct name DArkelf dagger slow) and stuff

Int Base

Dance of Medusa where is that one based on ? also int or p atk?

It is not magic skill, however the resistence depends on men.
Base rate is 40%

all "chance" skills have base chance.
this base chance is increase when you enchant them for chance.
also chance is increase with your buff/int/men/str/dex bonus

for example, root type skills like arrest is base on DEX but have base land rate of 80%

In fact i don't know if it's right because let's take for example
HEX from a SK: land rate isn't 80%..
but if u take gloom from a necro land rate it's a little more than 80%..
So u can't make an algoritm about chance / int.. because it's hard..
Maybe base rate it's acorded with 35 INT for example..
U don't know how much int u need to have for an exact 80 % or 50% or 100%.
So in conclusion u can't know :
Base Rate + u're enchanted lvl on skill + u're m. atk (int+weapon) + u're opponent M. Def. (MEN+jwls)

base rate is known for sure, it's put in crypted skills files of your client.
btw base rate is multiplied by INT bonus wich may be more than 1.00 but less than it too
INT bonus is calculated from a minimum INT wich represent 1.00
perhaps 35 INt like you said.
But it's not enough
final land rate depend of your matk int bonus, base land rate
but depend also of your target's mdef, MEN and resist buff
btw, enchanting for chance still increase base land rate
Anyway the higher INT you have, the more your debuff will land

Got base rate infos from a very good site, but i don't know that it is forbidden or not to write down the link here.
btw, if a skill is non-magic, but the debuff resistance is based on men,
then the success rate always depends on int?

Come on you make confusion again. You have the same success rates at lvl 76 as you have at lvl 78/80... I know what you're thinking as well. You think that if you enchant a weapon at lvl 1 it will surely break and if you do it at lvl 80 it won't right? It's a simple algorithm, it's not mentioned in it something like "if lvl==1 ->true; then enchant success==10%".

76 to +1 -- 82% success rate
77 to +1 -- 92% success rate
78 to +1 -- 97% success rate
79,80 +1 -- 97% success rate

For the 79/80 i'm not sure if it's 97% because NC Soft displayed the chances on c4 when it where only 78 not 80, and since then we didn't get nothing.
So for 79/80 it's just an assume maded by different sites/forums.

check l2calc for an accurate list of skill enchanting chances

That struck me bad. Guess i gotta start playing better servers. Sorry for my false comment.

There is no such thing as chance or luck...not in La2 ,not in the real world ,not anywhere, its all calculations ,statistics ,algorithms ,< or > ,probabilities but its never chance.