When 8th Edition came out the game of Warhammer 40000 was split into three different game types, Open, which was designed as a bit of an easy free for all, Matched, which had points value and a tournament feel, and Narrative.
Now Narrative in 8th was vastly different to the Narrative found in 9th edition. 9th Editions Narrative play is (for me) a Hybrid of Necromunda advancement and Matched play games with a slight twist. It doesn't have much in the way of a 'Narrative' to the game played. The 'Narrative' comes from the game after game you play and develop a slow story between your forces.
This is a very slow way of creating a narrative for your armies and miniatures, which requires you to play ALOT of games, again and again, to really get anywhere, especially if you do what the Narrative section of the Warhammer 40k rulebook tells you how to start up your Narrative Campaign.
Some folks don't have time for this, and with how Games Workshop shifts through editions, not playing a game for a few months can really put you behind.
The older Narrative missions, especially those found in the Imperium Nihilus books, concentrated on giving you a contained mission with a story, one that would have limitations on what troops you could have, if one side should have more power or points than the other, if a force could be exclusively characters against an army, etc etc. You could string 3 or 4 of these battles together to create a Narrative style campaign that doesn't require you to keep track of all of your forces. And it allows you to follow some of your fav instances in films, fiction, and even real campaigns.
Way back when, GW put out a campaign called 'Battle for Armageddon', which as we know is the second battle upon the blighted planet. The actual campaign is loosely based on 3 real-life campaigns from World War Two, one of which was the battle for Stalingrad. You can have a look at the original board game rule book here. Now this would require some pretty intense knowledge and digging through history to get your campaign running, alternatively, you can use movies and other media to get your Narrative ball rolling.
One of my Fav's to use is the Film Saving Private Ryan.
I'm going to do an old school Narrative Campaign article in the near future laying out how I would create a campaign for Saving Private Ryan in full, but here I will give you a quick breakdown of how you can use a film like Private Ryan to create yourself a mini Narrative campaign.
Of course, to begin with, one side will be the Germans and the other side would need to be the Americans. It wouldn't matter which race was used in either place as you are mainly using the structure of the film's action to represent your battles, the first of which would be the epic D-day beach landing.
You wouldn't have to make it a beach landing, but making it an attack on a heavily fortified position would be an ideal starting place. Using the Planetstrike missions from the Containment mission pack is a good start for this. A mission like Stanglehold with some tweaks is a good starting point. Not allowing a lot of vehicles for a start, allowing more power for the attacker and not allowing units to drop in will give a nice narrative feel and will replicate elements of the beginning of the film.
Mixing a bit of actual history into your campaign, your next mission could be another planet strike game, but a little smaller, something like 50pl, Planetary Assault Incursion mission could be used to represent the US Airbourne landings. Having rules like the attackers must be a complete infantry/walker force would be a good representation of this.
The next action set-piece shows an American force that has been cut in two by German Forces going through a town. Communication is difficult as both sides are taking out each other's runners (see the film for more context). Instead of using the film's main protagonists for this mission, I will instead concentrate on the communications aspect and base the mission on this. The Bitter Reversal from the Phoenix Rising Psychic Awakening book is perfect to reflect this aspect. Just change the forces to better suit your collections and have the story set as one force is trying to run through the patrols of the other to establish communications. I would also state that you use a lot of buildings and obscuring terrain for this game.
After this, we have a small bit of action of a gun nest being attacked by our small group of protagonists. This is where we can change the game type, going for a story driving Kill Team game rather than 40k, this change will give a different feel for your story-driven campaign, like your zooming in on a particular aspect of it. The change of pace will also feel different to your upcoming games. Your not just playing the same type of games over and over.
The rest of what I would do I will leave for my actual article, which will allow you guys the readers to have a go at a different type of Narrative campaign. Don't forget there are a lot of films and material you can manipulate to create a great story for your forces. I'll leave a few examples below and let me know if you guys would like me to convert any into an actual campaign series.
Marvel Avengers: Age of Ultron
A series of linking battles that pits a force primarily made up of Characters going against other forces. You could have all of the Phoenix Lords from the Aeldari taking on waves of Orks, Necron Characters taking on hoards of Adeptus Mechanicus Troops, or a Space Marines Chapter Command backed by Inquisitors taking on a Heretic or Genestealer Cult Uprising.
This film would be great as a multi-game platform campaign. You can incorporate real-life battles into your story, having the land games played in both 40k, Kill Team, and even Adeptus Titanicus. The ships attempting to aid with the evacuation you could play with games of Battlefleet Gothic if you have it, and the fighter battles can be represented by using Aeronautica Imperialis
Any others you can think of, please let me know.