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Exception To The Rule (OSP Campaign)

After a century without any external threat to bind them together, tensions between the Shelter Alliance's member nations have exploded into open war. The Outlying Systems Protectorate has claimed its independence, but how long it will last remains to be seen. The Alliance Navy readies itself for an assault through the Kribensis-Bethel hyperspace gate, aiming to crush the upstart rebellion in one swift stroke. Take command of the reactivated cruiser OSPN Exception to the Rule in the conflict's opening stage, and face down the behemoth that approaches.

Adds the Exception To The Rule singleplayer campaign to the campaigns/tutorials selection screen, with an original story told from the perspective of the OSP in the opening months of the rebellion. Sent behind enemy lines, your task is to disrupt the Alliance's plans for a war-winning offensive, until the OSP is ready to fight and win.

Completing the basic set of tutorials is strongly recommended before attempting the ETTR campaign. Completing the advanced set of missile tutorials is not required, but they discuss some tactics that may be useful during the campaign's more difficult encounters. The advanced set of carrier tutorials is not required.


Features a sequence of four missions, each introducing a different aspect of the OSP's arsenal and presenting a unique tactical puzzle, culminating in a challenging final battle with multiple endings. Each mission is roughly 30 minutes in length, and hands you a pre-set fleet of ships which you must deploy and command against a variety of opposing forces, with some surprises along the way. Acts as a continuation of the basegame tutorials, allowing new players to put the academy's teachings to use in actual engagements.

The ETTR campaign is fought from the perspective of the OSP for several reasons. Most importantly, the basegame tutorials all use Alliance ships, and so the game really needs an introduction to the OSP and their unique kit, which is less straightforward in its usage to begin with. Further, the AI is more competent and makes for a more intimidating opponent in its usage of Alliance ships.

ETTR's tutorialization is mainly delivered through text. If you don't like reading, then this is unfortunately not the mod for you. Voice acting is problematic because it restricts future changes. If the game's meta shifts around and I want to update a tutorial section to be more relevant, I don't want to have to run down someone to re-record a bunch of lines. The presence of voice acting is a large part of why the basegame tutorials are out of date in some areas and there aren't any more of them. Therefore, no voice acting will be added, even if people offer to provide it.


I believe this mod is an important landmark for Nebulous. Despite being an unofficial mod, ETTR is the first piece of real singleplayer content that Neb has. Because of that, I really wanted to get the story here right. This also may be the first introduction that many people will have to the Nebulous lore, since this mod is positioned as a new-player-friendly add-on to the basegame tutorials.

The most important main characters are taken directly from the game's published lore, chosen because they are actually mentioned as operating in the Kribensis system, where ETTR takes place. Same thing for the overall military situation in the campaign, and the wider context of the OSP's rebellion, it's all lore-accurate. My objective was to make this story match the devs' vision for the game as much as possible and I hope it shows.


Huge thanks should be given to the entire Nebulous dev team but especially their writer, Marshall, who has given the game a grounded and engaging setting and a wide cast of interesting characters. Without the devs' work, this mod couldn't exist. Thank you Marshall and company!

More thanks are due to the volunteers who played early versions of this mod and gave feedback on its gameplay and tutorialization: Corbeau, Zog, MrUnimport, Vren55, Tuna, Violence, Dargaribdus, Hardly, HarukaJunko, ShadowsSun, and ToastyMedic. Without them this would be a much less polished final release. Thank you all!

For any aspiring campaign modder who wants to check out the source code, go nuts.[github.com] Reading through the documentation of the Mission Graph Loader will also be helpful.

If you have played the mod and enjoyed it, why not give it an upvote? It helps raise this mod to the top of the workshop, so others can find and experience it. If you have feedback about the mod, you can leave it in the comments below, or go to the thread on the official Discord, in the #mod-feedback forum. Thank you for playing!

Citizens of Pyxis, Roclaren, Bethel, arise! We will not surrender to the rot and decay that surrounds us. Through perseverance and ingenuity, we will prevail! Long live the Outlying Systems Protectorate!