[Spoilers] Experience running ISAR and some concerns

[Myrion]

So I finally got around to running the introductory adventure, I Smell A Rat.

The players I got to run it for were newbies, this was their first introduction to Pen and Paper RPGs. (In fact, running this was a birthday present to one of them.)

The party consisted of a Swashbuckler, a Barbarian, a Bard and a Thief. Not optimal, but I thought that giving the Bard access to healing and everyone 2 healing potions would be enough to get them through at least the first part, at which point they'd be able to stock up again. The healing spells helped, but they still struggled heavily, which surprised me a lot.

They started out well enough, dealing with the spiders quite competently. The Swashbuckler got hit badly by the very first attack, but as it only happened once, and he began defending more successfully afterwards, it wasn't a huge threat. The party (apart from the Barbarian) did already have some trouble getting any damage through the DR, which in hindsight should've been a first red flag.
The Bard put Song of Echoes to great use as they cleared the cellar, which helped them find the Smuggler's Den (it pointed out a suspicious area of the wall that was different, which the Thief then turned into looking for a secret door). They looted that carefully, which was a cool scene, though I realized that the description of the den is a bit lacking.

In the sewers, they quickly found Merle's door, again using the Song of Echoes. Constructing an improvised bridge from the junk pile, they cross the sewage safely - except for the Swashbuckler, who jumped across!

That's when they hit the first big snag, though. They simply didn't have any way of dealing with the Rune-Limned gallery. The Swashbuckler was too Overconfident to play it safe, and obviously got hit again. The Barbarian made his save, and the Bard and the Thief looked at each other and tried to figure out any way to break the spell.
After several attempts, I allow the Bard to sing a Song to dispel the enchantment, at heavy penalty, but a Crit gets them safely past.

Then they run into the Peshkali - which would've just shredded them if I'd used its full potential. They didn't have close to enough skill or numbers to make it use up its parries, DR protected it from most of their attacks, making it hard for even the barbarian to deal the 10 damage in one go that are necessary to cripple an arm. Which they didn't know and couldn't figure out, as again, no one had the appropriate skills (also kinda my bad, I thought the bard knew this kind of stuff, too). So I told them to go for the arms, because they were about to give up on that, as they needed to deal 20 injury before they could even begin to deal with the arms.
Even with Deceptive Attacks (which only the Swashbuckler could reliably do), they barely hit.
With me cheating and not using the Peshkali's full potential, they eventually pull through.

That was the end of Session 1. While they told me it was a fun, challenging fight, it felt super stressful forme, as I had to cheat quite a lot.

Before Session 2, I make sure to read up on all the other monsters' abilities, so I wouldn't have to do that again or at least have a better plan for it.
I convince them to hire some support and they go and get themselves an initiate and an apprentice, so they have someone who can exorcise the altar and heal more, if necessary, as well as someone for magical threats (and the toxifier, though I didn't tell them that. They also stock up some Alchemist's Fire and Liquid ice.

They'd discovered the false wall previously, and now went through it to deal with the zombies, which worked very well, although their lack of vitals made them tricky to deal with for anyone who didn't have the Barbarian's raw damage. I kept the number of Zombies low, and that was a good decision.

Instead of exploring, they end up going straight to Merle, encountering and avoiding a fight with rock mites on the way.

I may have misread Merle, but he ended up not giving them much trouble at all, as the bard uses Daze on him as much as he can and Merle resisting horribly. But at least this way the Bard was useful - unlike the Thief. The thief just doesn't deal enough damage to get through DR, even from behind (not having invested in Expert Backstabbing).
The Swashbuckler doesn't roll great on damage, again leaving the big part of the work to the Barbarian.

It felt like the adventure shut down many of the combat options that characters other than the Barbarian need to be effective. No Vitals, no Knockdown, DR etc make it very hard for most chars to even deal damage. The challenges that flat-out require a Wizard and/or Cleric were also somewhat surprising. I get niche protection, but that no-one can cover in a pinch was a bit frustrating.

Of course, the players didn't bring a lot of system mastery, but I feel like that shouldn't be required for Dungeon Fantasy, yet it really feels like a balanced party and a good deal of system mastery are a hard requirement.