The catatonic and autistic protagonist who lives in a Dungeons and Dragons (which I know almost nothing about) style medieval esthetic universe suffered a horrible loss of family and friends when he was a kid at his village by the hands of one of the vilest creatures this universe established the green skin pointy nose lizard eyes goblins who will survive and reproduce by any means and are disgustingly evil and sadistic. From this trauma and hate that he bears he vows to himself that he will become the Doomguy exterminator of goblins and make the goblin race extinct from this tabletop game fantasy universe.
Goblins are like an insect pest for example rodents in this world people don't pay much attention to them, they underestimate them and let inexperienced adventurer scrub deal with them and of course much like pest control of our universe people will not pay much attention to the importance of your job and only call you when there is an infestation at their own doorstep.
So pest control slayer guy devotes his life to this one autistic goal (the goal itself isn't autistic its the way he approaches it) to exterminate all goblins and is joined by other adventurers he saved and who were sent to join him by their respective factions in dealing with this grave pest that we are led to believe if not dealt with will cause some bubonic plague level damage to all races in this world or wipe them all out and replace them to be on top of the race hierarchy civilization food chain and dominate this world. There are more characters that have some bonds (if you can call them that) with the MC but their existence from what I can see is so purely for plot driving (Pest control guys company at least have some semblance of a personality and purpose no matter how bland it is) and for having the MC something to do.
And so on their extermination mission, these tabletop nameless characters usually go on goblin quests together usually spouting generic fantasy lines and lore and then in between taking their rest in a generic fantasy medieval small towns, villages, and cities where they meet more tabletop figures that need them for or tell them about the stuff I said above and of course adventurer birocratic stuff and rankings that serves almost no point in this manga beside for forcing characters to talk on another (the guild birocracy in the story which encompasses a big portion of itis draining and serves no purpose besides for telling people about quests and forcing character interactions and plot in an unengaging and boring way).
So the plot moves on the note of this pest control fantasy group maybe bonding in the future and not doing this extermination business like mindless drones or maybe dying in the line of job duty who knows and Pest Control-san maybe overcoming his autism and catatonia and becoming a healthy emotional human being if possible who knows how to interact with people on some emotional level or maybe bonding with someone on a deeper level himself, whilst saving the world from a doomsday goblin infestation or conquest and exterminating all of them or not and him getting some crazy revelation about them or him or the world or something-something (like gee what happens when I exterminate a species from an ecosystem does that have repercussions on other lifeforms or crap I'm not a pawn of this tabletop game I am me and I will continue working in fantasy pest control for a living) which I think is a slim chance and will be added in only to justify the actions he has taken thus far because of the prohibitions the story and the way it was written imposed.
Somewhat SPOILERy from here if you haven't read anything yet:
The intellectual appeal of this universe (and its narrow and not very engaging by the narrative fact of it being constrained as a tabletop game manifestation since its attachment quality to the fate of the characters and the plot is lost being viewed through that prism) on some level is the system of dice tossing that is an unofficial hinted physical law of the universe which is in the continuous war between the Gods of Chaos, Chance, and Destruction and Gods of Order, Fate, and Creation that are the creators and govern the universe (I think that their properties correct if not) which is manifested through the dice toss that determines what will each entity in the world do. The Dice is sorta like their compromise on what will happen next however it is hinted that Goblin Slayer sorry Pest Control guy defied the toss of the dice in few instances when he and his companions should have died (I haven't found any explanation how besides he's special in his slaying autism and MC and it will amount to something) and he turned it around miraculously wow since you can't have one of the companions dying yet. It is hinted that he is defying the physical law of causality that the dice toss has in his slaying autism and care of, not anyone dying by the hands of goblins and in his vengeance and pure hatred for them which eh doesn't make a lot of sense nor is that engaging as reason or motivation.
Overall the enjoyment part will be the crafty ways in which goblins will be slain and using some fantasy items in clever nuanced ways to outsmart even stronger foes or big hordes, brief military tactics on how to fight goblins which are valid, bright and make sense, the appeal of the exterminator aura which the Pest Control guy gives off and his unusual look Doomguy look that comes with it and the skills his companions have and few of their interactions and that's about it for them (I couldn't get myself to give the characters a higher grade since even a few moments when they escape from their generic role and personality and act somewhat human it's still so alien because of the rules of the world and mission they are doing (the talk revolves about arguments about goblins, goblin slaying or about the husk of the personality of the MC or his robotic responses that are intended for comedy but are boring and annoying than funny in my opinion and reaction to them, or giving advice on boring out of nowhere romantic interests which in the way hanldle serves for the Pest Control Guy to have girls feeling for him harem conflict or some crap which in the way so far handeled added nothing for the story and gave a possible bland motivation rather than a personality to the MC so far). They are trapped literally trapped in their role as the main MC backup and tools it like he is playing a tabletop with their lives destroying their character development in the process and the possibility of them forming an interesting group that's relatable and which fate you care about.
To conclude this dark fantasy is drawn very good and the battles, gore, and fighting is fairly well done and is enjoying to look at, the military tactics make sense and are interesting and there is some minuscule discussion about determinism and free will. Other than that the characters are reduced to tabletop figurines constrained by the aforementioned stuff about the narrative and the goblins are pure evil pests and thus far I'm not seeing more of them of trying to be bubonic plague rodents or trying to become the dominant aha you taught we were weak but we are the main threat race that will try to torture and subjugate others in this world. So the main plot is reduced to being driven by this extermination mission that may at some point impose some moral or universal balance questions rather than simple necessity which I would have given a higher grade for the story if it handled it better and more belivebly and not constraining in this tabletop DnD format in my opinion.
Overall I couldn't give it a higher grade than 3 which is poor since the manga, in my opinion, isn't decent enough with its way of storytelling, universe construction decisions, characters and their development (which is one of the main reasons for me for grading it this despite it being rationalized of being a tabletop game that is not at all for having uninspiringly and boringly written characters) and the plot which is centered around isekai pest control thus far.
