There was a time when I scoffed at prewritten adventures in roleplaying games, especially in D&D. The point of the Game Master is to create their own setting and plot and let the players experience what you want them to experience. Using a premade adventure is going to take that point away, and most likely the adventure will suck due to its rigidity/vagueness/difficulty. I went and created my own worlds, my own plots and my own encounters. Only fools used premade games. Then Dark Heresy happened.
Dark Heresy is a roleplaying game that takes place in Warhammer 40k-setting. The players are Acolytes of an Imperial Inquisitor and take roles such as a Techpriest, a Psyker, an Arbitrator or a Cleric, amongst others. While obviously marketed at people who already know all about 40k, I imagine there might be a few people who don’t know anything about it and still want to try out Dark Heresy. These people are confounded with a new system, weird character classes and only a vague idea what the game is about. One could read the enormous background of the 40k setting, but that would probably take a long time. A better way to instantly get to know the game would be a some kind of tutorial. Like a premade adventure.
Dungeons & Dragons 4th Edition’s Dungeon Master’s Guide has a short, introductionary adventure at the end of the book. It consists of a village with some important people characterised and a simple background plot: A group of Kobolds living in an old manor have raided a wagon caravan, and someone needs to retrieve the cargo. The section is followed by a simple dungeon with kobolds, traps, terrain features and a boss monster in the end. The adventure tells the DM and the players what the game is about: Heroes going to interesting places, getting a quest, going to a dungeon and fighting monsters. It perfectly illustrates what the Intended Game Experience is.
Same thing with Dark Heresy. There is an adventure in the book to introduce the players to what the game is about: Going to wretched places, meeting mutants, fanatics and heretics, finding out eldritch secrets and then dispensing Imperial judgement to the heretics and appropriate mutants and fanatics. The game is harsh and someone, perhaps even everyone, will probably die. The adventure was not the thing I was expecting, as it was rather rigid. And that was the moment I realized that every roleplaying game should have a premade adventure somewhere.
Bliaron, a game that my friends made recently and a game I analysed, did not have a premade adventure. It had several pages of game ideas, sure, but not an adventure. A single, prewritten adventure would have given a focal point to which attach all the other information the book contained. And yes, I know that Bliaron is meant to be a setting where you can try anything. That is not an excuse. Then you just put everything in your adventure.
An example premade adventure: The players are newly discovered mages and have been brought to join one of the three Sahens (mage cults). Before they are given a rank inside the sahen, they must prove themselves by fulfilling three tasks: Retrieving a thingamajig from a monster-infested cave (treasure hunt and monster-slaying), settling a labor dispute at a nearby magic-stuff farm (politics) and investigating a strange ruin filled with ancient secrets (myths and mystique). Meanwhile their instructor is acting somewhat suspiciously, and if the players investigate further, he is revealed to be a black hand (rogue mage), who is plotting the downfall of their sahen (conspiracies and mysteries). Even if the quality of the adventure isn’t very high, the players and the GM can still identify the most fun part of the game and keep doing that.
The moral of the story is: A premade adventure is a tutorial to the intended playing experience of your game. Always provide one for your roleplaying game.