I've encountered a few recent games, namely Nox Archaist and Stranger of Sword City Revisited, where even blunt weapons don't work *at all* against skeletons unless they're magical or enchanted in some way.

On the other hand, for the game I'm designing in my head, I think that would make them too powerful, since the design allows for skeletons in the party.

Since magic holds them together, why would a cut make any difference? Those bones are probably cracked and split many times already anyway, and again, the bones are held to each other and made to move by magic, so splitting one, or a few, in two likely won't matter much for that magic, just adds one, or a few, pieces to the count. But if it'll need to hold together and coordinate countless tiny splinters or even basically bone dust, it'll likely be too much.

If Samurai is Wizardry like Gish, then Samurai. If it's not, then neither. Take something which can actually cast spells like Paladin and Ranger, or Barbarian who can actually fight and look cool while doing it.

Until you discover that the game allows Fighters, but not other fighter-types, to cast spell.

(One way this could happen is if a game has both advanced classes and subclasses, but has the restriction that you can't have both on the same character, and Fighters are the only base class that's a fighter-type. Also, there are games where Paladins and Rangers don't cast spells; Saviors of Sapphire Wings is one (where Samurai, while not spellcasters, have the ability to hit multiple enemies at once, which is quite handy).)

i dont like hybrid classes as they are usually fail in both of their roles, too many games made for minmaxing ,if you dont put all skills into one skill then it will be useless like disarm trap/ lockpick etc.

You shouldn't play Pathfinder than, because their Hybrid classes are more powerful than parent classes, especially Shaman and Skald.
If Fighter casts spells, then he's not a Fighter.

And Paladin or Ranger spells aren't usually good, but: a) they usually have other skills/abilities which contribute to the party; b) they have more flavor.

My problem with the Fighter is that it is such generic fantasy archetype that it is really boring. Plus, they are one trick pony, only thing they know is fight. Everybody fights in RPG, but usually they do it in more interesting way than the fighter.

does that really work?

Until someone actually manages to hit you, yes.

Sounds a bit like a Metal Slime from the Dragon Quest series.

For those not aware, here are some traits of this particular monster type:
* Low HP. (3 or 4 for a plain Metal Slime, and only the most powerful can even *think* of double digit HP.)
* High defense, enough so that most attacks have a 50% chance of dealing 1 damage, otherwise don't do any. (Note that critical hits ignore defense in DQ.)
* Immune to magic. (Sometimes spells that would remove the enemy without yielding XP are excluded, and breath attacks work on them in DQ3 and original DQ4 (though they only 1 damage in the latter).
* Not particularly dangerours.
* Likes to run away.
* If you defeat one, you get a lot of XP, to the point where, in much of the series, killing them becomes the only practical way to reach high levels. (Note that you don't get XP if it runs away.)

(By the way, it's not that easy to run from a Metal Slime, but if you try and fail, it's quite likely that the Metal Slime will run away.)

It occurred to me that the Dink monster from Wizardry 4 is similar, but with low AC instead of defense, and without the XP yield. (Note that the Dink in Wizardry 2 is not nearly as hard to hit.)