We found the core warp travel rules of the Warhammer 40k RPG Rogue Trader to be too simplistic, but the rules from the Navis Primer expansion to be too complex, so we mashed them together to create our own!
You can download these in a print-friendly PDF here.
Pre-flight checks
The Captain spends an hour warding away ill-tidings. Failure to do so means any ‘9’ rolled by the navigator automatically fails that test.
Some might insist on booming out hymns through the ship’s vox-casters and require their crew to stand alert and sing fervently in praise of the God-Emperor. Others demand the flogging of the crew by their taskmasters, so that their mingled blood might strengthen the vessel’s machine-spirit. Lots may be drawn throughout the ship and a single crewman selected to be jettisoned into space, so that his drifting soul might distract any Daemons lurking to ambush the ship as it translates. Some captains may consider it unlucky for the crewmen to have tokens representing chance, such as cards or dice, which might jeopardise Warp travel, and make a thorough search among the crew to locate and destroy such items.
Voyaging into the sea of souls
1. Determine Duration of passage
The GM comes up with a duration (using the Route Stability and risks table below if it is an unknown route) and the Navigator makes a Navigate (Warp) test to get a close estimate. A Detailed chart (either made by the players or purchased separately) provides a +20 bonus, a Basic chart gives +10.
2. Locate the Astronomican
The Navigator makes an Awareness +10 test, every DoS (Degree of Success) adds +10 to any further Navigate (Warp) tests and vice versa. 3+ DoF (Degrees of Failure) indicate the Astronomican cannot be found, imposing a -60 on the Navigate (Warp) test for Step 4.
3. Consult the instruments
For players: cross your fingers. This is a secret GM roll! The GM makes a Navigate (Warp) +10 test to detect any phenomena or turbulence on the journey ahead, granting a +20 bonus to any rolls on the Warp Travel Encounters table during the ‘Translate and steer the vessel’ stage if successful.
4. Translate and steer the vessel
The Navigator makes a Navigate (Warp) test (-60 if the Astronomican cannot be located) with modifiers for Route Stability. If the test is failed and a ‘9’ is rolled on either dice, the GM messes with their final destination.
Roll once on the ‘Warp Encounters’ table for each 5 days (or part) in the warp. +20 on each roll if Step 3 was successful.
Have a look at our Expanded Warp Encounters table or download the PDF.
5. Leave the warp
The Navigator makes a Navigate (Warp) -20 test. Failure indicates the ship is off-target and could land dangerously close to a planetary body or the incorrect side of the system.
Congratulations! You have either arrived successfully at your destination or translated into a star and have melted.
Charting the route
A Navigator who successfully plies an uncharted Warp route can attempt to chart that route for future reference.
This requires a Trade (Astrographer) +10 Test if his vessel arrived on target, a Trade (Astrographer) -10 Test if it was slightly off-course, or a Trade (Astrographer) -30 Test if it was severely off-course. A warp route that shifts from voyage to voyage (see the Route Stability and risks table below) cannot be charted.
If he passes the Test, he creates a Detailed chart. If he fails, he creates a Basic chart, but if he fails by three Degrees of Failure or more, he fails to create a chart at all. A Navigator is duty-bound to present a new chart to his House, and providing his House with such valuable knowledge grants him considerable prestige. The Explorers’ Profit Factor increases by 1, plus an extra 1 for every full 180 days duration of passage of the journey that the Navigator charted.
Emergency drop from warp
If you roll equal to or under the Encounter roll, you can drop from warp and ignore (or minimise) the Encounter’s effects.
Make an immediate Step 5 – Leave the warp test at an additional -20, so a Navigate (Warp) -40 in total.
Route Stability and risks
| D10 Roll | Effect |
| 1 | Fair winds: +20 to Navigate (Warp) tests |
| 2-3 | Stable route: Navigator gets +10 to any tests to chart the route |
| 4-5 | Indirect path: Add +D5 days to the journey |
| 6 | Haunted passage: -20 to any rolls made on the Warp Encounters table |
| 7 | Surly route: Add +D10 days to the journey and the Navigator suffers -10 to Step 1: Determine duration of passage |
| 8 | Untraceable trail: -20 to Navigate (Warp) tests and the route cannot be charted |
| 9 | Lightless path: Astronomican automatically cannot be found in Step 2: Locate the Astronomican |
| 10 | Byzantine route: Multiply journey length by D5 |