I just don't like the navigation rules. The ones in the core aren't enough. They're vague, so I have to wing it all the time. And there's no objectivity in winging it, and the players know it, and don't feel it's fair when bad stuff comes their way. Navis Primer went the extreme in the other direction. A few voyages under your belt and WHAM!, your ship is crippled and half your crew is down. I wanted something that results in common setbacks with a miniscule chance of catastrophe, given that proper precautions are taken. And I wanted a system that made it plain that these precautions were an absolute necessity or you'd run into the Navis Primer problem. I loved the way the Navis Primer expanded Warp encounter, but I don't think they were all play-tested or the authors would have run into the same problem.
So here you go...
Navigation
1. Determining the distance (as a function of successes needed in Step 3)
a. Determine the number of steering checks needed as follows – Travel within a sub-sector requires 1d5 successes. Travel to an adjacent sub-sector requires 1d10 successes. Travel across a sub-sector requires 1d10+2 successes per sub-sector crossed. Multiply the successes needed by the conditions at the target destination (see multipliers below). Resolve this as an extended action. Each check takes 1d10 days of “ship time” while 1d100+20 days pass in real space. Example: The explorers are travelling from one system within the Accursed Demense to another system within the Accursed Demense. They would need 1d5 x 2 successes to reach their destination.
i. Stable 1.0
ii. Unstable 2.0
iii. Surly 4.0
iv. Haunted 8.0
b. Other temporal modifiers
i. Markov Drives reduce time passing in real space as normal to a minimum of 1 day
ii. Starcharts reduce time passing in real space as normal to a minimum of 1 day
2. Divining the Auguries
a. Navigators can use their Psyniscience skill (with House rituals) to perform this check. Missionaries can use Common Lore (Ecclesiarchy). Anyone can use Deceive at -20 (be sure to give the crew their opposed scrutiny check at Crew Rating level). Good portents (passing the check) means you can continue to the next step. Bad portents (failing the check) requires someone of proper authority (usually the Captain or a Missionary) to calm the crew. Perform a Charm (-10 for each degree of difficulty the previous check failed by) check. Failure means the ship must wait 1d10 days while proper rituals and prayers are performed, or the crew immediately suffers morale damage -10 (-10 for each additional degree of failure), AND EVERYONE is -10 (-10 for each additional degree of failure) with ALL checks until the Warp is exited. This means the crew rating is also affected.
3. Locating the Astronomicon
a. Navigator tests Psyniscience
i. Obscured -10
ii. Shrouded -20
iii. Lightless -40
iv. Warp Antennae +20
Success means continue to step 4 (+10 to steering checks for additional degrees of success), while failure means -10 to steering checks for each degree of failure.
4. Steering the Vessel
a. Modifiers
i. Quality Charts -20/0/+10/+20 (poor,common, good, best)
ii. Uncharted -60
iii. Warpsbane Hull +10
iv. Bellecane Geller Field +10
v. Fleet Flag Bridge +5
vi. Runecaster +20
vii. Warp Sextant +20
viii. Stable Route +10
ix. Unstable +0
x. Surly -10
xi. Haunted -20
Successes accrue toward the required distance. Runecasters double the number of successes (so do Miloslav drives if you haven't nerfed them). Failure means there is an encounter. Bellecane Fields add 2 degrees of failure. Warp Antennae and Miloslav Engines add 1 degree of failure. Warpsbane Hulls reduce 1 degree of failure.
Failure Aetheric current
Failure by 1 degree Aetheric Breakers
Failure by 2 degrees Warp Sickness
Failure by 3 degrees Warp Storm
Failure by 4 degrees Warp Monster
Failure by 5 degrees Daemonic Incursion
5. Leaving the Warp – Make a Navigation (Stellar) check. Roll 1d100 + 20 to determine the number of days travel to the target destination (-1d10 additional per degree of success, +1d10 per degree of failure).
Warp Encounters
Aetheric Current – The voyage might seem short or long but accurate time is lost and cannot be corrected until the ship leaves the Warp and the Astropath re-establishes contact. Increase or shorten the voyage by 1d100 days. When rolling a 01 or 100 treat as Righteous Fury (or negative Righteous Fury), roll again, and add (or subtract) the additional number of days.
Aetheric Breakers – The Navigator makes an awareness check. The Pilot then makes a Piloting check (+10 for each additional degree of success made by the Navigator, or -10 for each degree of failure) to avoid or the ship takes 1d10+2 damage (this assumes Mathhammer, otherwise 1d10+14), ignoring shields. On a roll of 10, take a critical hit in addition to the hull damage (only exterior components can be affected by this critical).
Warp Sickness – There are 3 types of Warp Sickness (roll 1d10), the one that causes actual illness (1-5), the one that causes insanity (6-8), and the one that causes corruption (9-10). Test Toughness or Willpower, as appropriate. If the Warp is exited for any of these maladies the voyage has to start over, albeit from deep space.
Illness - The crew makes a Toughness check. Success indicates the crew has resisted the effects of the illness so far (and will continue to do so for additional checks for each additional degree of success). Failure means 1d10+2 Crew Pop fall sick (+1 for each degree of failure). All but 1 point of this is counted as temporary crew population loss. The one point is permanent. As long as the ship stays in Warp OR any crew are still affected, roll again each steering check (or each day if the Warp is exited). Medicae skill can be used to alleviate the sickness (while still in the Warp), or cure the sickness (after the Warp is exited). Success with the Medicae skills alleviates (or cures) 1 point of crew population (+1 per additional degree of success), to a maximum of the healer's Int bonus. Once the Warp is exited AND all surviving crew is cured the illness ends.
Insanity - The crew makes a Willpower check. Success indicates the crew has resisted the maddening effects of the Warp so far (and will continue to do so for additional checks for each additional degree of success). Failure results in 1d5+2 Crew Pop becoming mad. The cure for this malady follow the same routine as above. The differences are that 1) additional checks grow, so 1d5+3 with the second check, 1d5+4 with the third, etc., and 2) the +2, +3, etc. loss is permanent.
Corruption - The crew makes a Willpower check. Success indicates the crew has resisted the corrupting influence of the Warp so far (and will continue to do so for additional checks for each additional degree of success). Failure results in 1d5+2 Crew Pop falling to the Dark Powers. These need to be "cured" as above, but all are permanent losses. The ship's population of mutants and hullghasts is increasing. Additional effects might include the ship becoming Haunted (Rogue Trader p.198) or the crew forming a Death Cult (as they hunt down the survivors).
Warp Storm – The Navigator makes an Awareness check. If successful, the ship may exit the Warp (though having to start the voyage over). If unsuccessful (or if the person in charge is unwilling to exit the Warp), the Pilot has to make a pilot check. Failure results in the vessel taking 1d10 damage (once again, assuming Mathhammer, otherwise 1d10+12) to hull integrity, ignoring shields. Following this, check to see if the storm has abated. Roll 1d5. On a roll of1 the storm is over. On any other roll, it continues. Once again, the ship may exit the Warp or continue to fight the storm. Steering the Vessel still continues (1 steering check for each round of fighting the storm) and it is entirely possible for a ship to complete its voyage and exit at the destination all while fighting a Warp Storm.
Warp Horror – A monstrous Warp creature attacks the vessel. The Navigator makes an Awareness check. If successful, the pilot makes a piloting check (+10 for each additional degree of success made by the Navigator's check). If the Navigator fails the ship is taken by surprise for a number of rounds equal to the degrees of failure. If the Pilot fails, treat as a Stern Chase (Rogue Trader p. 216). The creature's pertinent characteristics are S3, WS 50, 1d10+2 (assuming Mathhammer, otherwise 1d10+14), Crit 5, Armor 0, Hull 50. It might try to ram if wounded. Evading this monster results in fleet formations becoming separated. This can be your "battle in the Warp."
Daemonic Incursion – Increasing incursion begins as swarms of demonic bugs begin attacking the crew and machinery in an attempt to disable the Geller Field. The Navigator can dispel this attempt with a Test of the Soul (Navis Primer p.32). If the Navigator fails the Test of the Soul, the ships and crew will be attacked by the swarms. Inflict 1d5 on Hull Integrity, Crew Population, and Crew Morale, AND each player takes 1 damage (no armor, no toughness bonus, no force shields, no nothing). The Navigator must continue testing until successful.
Routes of the Koronus Expanse
The Maw – the Maw, from Port Wander to Footfall, requires a single success to navigate. If any navigation test fails, the Navigator can avoid the encounter by dropping out of the Warp to any of the Stations of Passage. This can be done 4 times in a single passage, but no station can be visited more than once.
Location Routes Astronomicon
Winterscale’s Realm Stable Visible
Ragged Worlds Unstable Obscured
Heathen Stars Stable Visible
Accursed Demense Unstable Obscured
Cinerius Maleficum Unstable Obscured
Cauldron Surly Shrouded
Rifts of Hecaton Haunted Lightless
Foundling Worlds Surly Obscured
Unbeholden Reaches Haunted Shrouded
Charting Routes
Charting new routes requires successful use of the Astrography skill.
Stable routes are +10 to chart
Obscured routes are -20 to chart
Shrouded routes are -50 to chart
Lightless routes cannot be charted
And for those of you with a penchant for navigation, apply penalties to this check if the Astropath can't reliably fix the exact time. I use -20 for indirect timing (Class 3-5) and -40 for non-referenced timing (Class 6-8).
A big thank you to Errant for having me look this up. It was stuffed in the files of my last campaign (which only recently ended), and I'd have lost it for sure by the time I got around to running another.
And of course, all of this stuff is modified rules already in existence from Rogue Trader and Navis Primer.
Edited by Errant Knight