For example, how do they compare to Dark Heresy characters? And do they have their own rules that mean you can't simply mix and match?

Only War is essentially Dark Heresy v1.4. You can mix-and-match, but the best results mechanics-wise would be obtained with Black Crusade, as that is the predecessor with the most similarities mechanics-wise. Those before BC (DH, RT, DW) had a stricter class-based advancement and a larger skill system - especially the latter may produce problems, as for example a Dark Heresy character has three skills (Survival, Tracking, Wrangling) where a OW character has one (Survival). Also, you'll have to decide for one system's combat rules.

Well I have zero interest in Black Crusade. I burn Heretics not join them! So the combat system is different too? Hmmmm….as for the skills, those might be fixable with house rules, probably narrowing DH skills down to the Only War version assuming that wouldn't impact balance too badly.

There are two large differences in combat: Firstly, almost every attack is now a half action. This makes for more fluid and moving combats rather than just slugging it out with Full Auto, which brings us to the second difference - Single Shot now has a +10 bonus, Semi-Auto is +0 and Full Auto is -10. This way, weapons aren't graded along "Does it have Full Auto or Accurate? No? Next!" anymore.

Riggswolfe said:

Black Crusade is a great source of additional information. It can allow you to make those arch-nemeses for your campaigns. Black Crusade is also the origin of expanded skill rules; -20/0/+10/+20/+30, as well as the foundation of the more fluid advancement system we see in Only War . It's at least worth a "thumbing through" at you FLGS.

-=Brother Praetus=-

Starting gear is a bit advanced as opposed to what DH characters can get (heavy weapons specialists getting missile launchers/heavy bolters, weapon specialists having access to meltaguns, etc.), but I think I saw someone say that DH characters have cheaper advance costs, so XP wise the DH character will generally be superior to an OW character. Of course, none of this is accounting for how OW characters can horde up XP and buy top tier talents early and what not.

System wise, a few key rules are different, but the characters should be able to "exist" in each others' system. Things still have wounds, TB + AP reduces damage, pen reduces AP, the core statline is the same, etc.

If I ever had multiple characters from multiple systems, I would just run it where a character uses their own rulebook to govern their own actions, and how they process whatever is incoming. That is to say, if both a DH and OW character are at my table, the DH character would take full round Full Auto attacks at +20 (counting the DoSs DH's way), and the OW character would make half round Full auto attacks, at -10 (or is it -20) using OW's system for counting DoSs. Confusing I know, but once you get used to it its a tad bit simplified for how each is balanced (in other words, not just porting a non ascended DH psyker and letting them use the fettered/unfettered system)

KommissarK said:

This literally has me imagining a bunch of Catachans with a Battle Sister in their group, and she's on top of the hill pretty much posing with a bolter firing round after round, and the Catachans kinda wondering why she's taking so long but not arguing with the results.

I've played in mixed setting games (mainly RT/BC, with a bit of DH), and we dominantly used the BC rules… I don't really think you couldn't use DH and OW next to each other, but I would suggest sticking to one and only one Psychic rules set (oh no, they brought back Psy heal, no they'll never die).

It took me all of 40min-1hour to convert the DH careers over to Only War. I figure just use the OW rules for combat and how they acquire gear. I wouldn't mix already existing DH characters into an OW game though.

My wright up for those interested. The first part is a rough class breakdown for only war characters. For the conversion numbers I just averaged them out and rounded up or down as felt appropriate.

Troopers (note: ap=starting aptitudes)

Heavy gunner: 6ap, 5 skills, 4 talents
Medic: 6ap, 3 skills, 3 talents
Operator: 6ap, 3 skills, 3 talents
Sergeant: 7 ap, 3 skills, 3 talents
Weapon Specialist: 6ap, 4 skills, 4 talents

Specialists

Commissar: 7ap, 4 skills, 5 talents
Ministorum Priest: 7ap, 4 skills, 6 talents
Ogryn: 6ap, 1 skill, 3 talents
Ratling: 7ap, 3 skills, 5 talents
Sanctioned Psyker: 6ap, 4 skills, 2 talents
Storm Trooper: 6ap, 5 skills, 4 talents
Tech Priest Enginseer: 7ap, 5 skills, 5 talents

Conversion numbers:

6 starting aptitudes, 3 skills, 4 talents

Careers that need Conversion

Adept
Arbitrator
Assassin
Scum

Adept
Characteristic Bonus: +5 Intelligence
Starting Aptitudes: Intellignece, Knowledge, Fellowship, Tech, Defence, Social
Starting Skills: Trade (Copyist) or Trade (Valet), Common Lore (Imperium), Scholastic Lore (Legend) or Common Lore (Tech)
Starting Talents: Light Sleeper or Resistance (Cold), Sprint or Unremarkable, Weapon Training (Solid Projectile, low-tech)
Starting Equipment: Stub Revolver, Staff, Administratum Robes, Auto-quill, writing kit, chrono, data-slate
Starting Wounds: 6+1d5

Arbitrator
Characteristic Bonus: +5 Toughness
Starting Aptitudes: Weapon Skill, Offense, Toughness, Defense, Social, Willpower
Starting Skills: Common Lore (Adeptus Arbites, Imperium), Inquiry
Starting Talents: Quick Draw, Rapid Reload, Weapon Training (Solid Projectile, low-tech)
Starting Equipment: Shotgun(pump action), Carapace Chestplate, Truncheon
Starting Wounds: 10+1d5

Assassin
Characteristic Bonus: +5 Ballistic Skill or Weapon Skill
Starting Aptitudes: Ballistic Skill, Weapon Skill, Finnese, Offence, Agility, Perception
Starting Skills: Awareness, Dodge, Acrobatics
Starting Talents: Ambidextrous or Unremarkable, Weapon Training (Las, Solid Projectile, Low-tech)
Starting Equipment: Shotgun or Long-las or Autogun, sword, knife, Black Bodyglove
Starting Wounds: 10+1d5

Scum
Characteristic Bonus: +5 Fellowship
Starting Aptitudes: Ballistic Skill, Finesse, Fellowship, Social, Agility, Fieldcraft
Starting Skills: Charm or Dodge, Decieive, Awareness, Common Lore (Imperium)
Starting Talents: Ambidextrous or Unremarkable, Light Sleeper, Weapon Training (Solid Projectile, low-tech)
Starting Equipment: Autogun or shotgun, autopistol, knife, street ware or rags or dirty coveralls
Starting Wounds: 8+1d5


I'm going to let them pick a regiment or create one themselves. I'm most likely going to be running a DH themed game using OW rules. So no armoured regiments or things of that nature.

Someone did a re-work of your work on another forum funnily enough.

Adept
Characteristic Bonus: +5 Intelligence
Starting Aptitudes: Intellignece, Knowledge, Fellowship, Tech, Defence, Social
Starting Skills: Trade (Copyist) or Trade (Valet), Common Lore (Imperium), Scholastic Lore (Legend) or Common Lore (Tech)
Starting Talents: Light Sleeper or Resistance (Cold), Sprint or Unremarkable, Weapon Training (Solid Projectile, low-tech)
Starting Equipment: Stub Revolver, Staff, Administratum Robes, Auto-quill, writing kit, chrono, data-slate
Starting Wounds: 6+1d5

Arbitrator
Characteristic Bonus: +5 Toughness
Starting Aptitudes: Weapon Skill, Offense, Toughness, Defense, Social, Willpower
Starting Skills: Common Lore (Adeptus Arbites, Imperium), Inquiry
Starting Talents: Quick Draw, Rapid Reload, Weapon Training (Solid Projectile, low-tech)
Starting Equipment: Shotgun(pump action), Carapace Chestplate, Truncheon
Starting Wounds: 10+1d5

Assassin
Characteristic Bonus: +5 Ballistic Skill or Weapon Skill
Starting Aptitudes: Ballistic Skill, Weapon Skill, Finnese, Offence, Agility, Perception
Starting Skills: Awareness, Dodge, Acrobatics
Starting Talents: Ambidextrous or Unremarkable, Weapon Training (Las, Solid Projectile, Low-tech)
Starting Equipment: Hunting rifle or Shotgun, Bow or Good craftsmanship Mono-Sword, knife, Black Bodyglove
Starting Wounds: 10+1d5

Scum
Characteristic Bonus: +5 Fellowship
Starting Aptitudes: Ballistic Skill, Finesse, Fellowship, Social, Agility, Fieldcraft
Starting Skills: Charm or Dodge, Decieive, Awareness, Common Lore (Imperium)
Starting Talents: Ambidextrous or Unremarkable, Light Sleeper, Weapon Training (Solid Projectile, low-tech)
Starting Equipment: Autogun or shotgun, autopistol, knife, street ware or rags or dirty coveralls
Starting Wounds: 8+1d5

I really like what you've done with the DH careers. I've done something similar and I'm working on an adaptation of the character creation system adapted from the regiment creation system.
Something like:
Homeworld--Inquisitor (replacing CO)--Ordo (instead of regiment?)--Philosophy (maybe this could even be lumped in with Inquisitor)--Training--Divination (an expansion of the imperial divination chart from the original DH rules, I always liked it.)
Then add the specialty/career.

Droma said:

One thing I've always thought of is that the games are not designed to be compatible. The games are all different, but because they are based in the same game world, and use the same basic rules, FFG decided to give players the possibility to integrate the different games. Only War and Dark Heresy (or Rogue Trader/Deathwatch/Black Crusade) are not meant to be used together, but they can be used together if you really want because they use the same basic rules and stats. It’s similar to D&D (3.5 if I am not mistaken) and the Star Wars RPG (or Gamma-world or Pathfinder might be a better example… any game using the Open License I guess), the games are very different but both follow the same basic line of rules and thus they could, in theory, be spliced. These games are not meant to be equal or compatible they just happen to be. FFG gave us the option in the other books with the way to do it because they knew we might want them to be compatible and it was relatively easy back then. Only War is something of a culmination of all the other books in a lot of ways and I think with some tweaking, which is the point of the beta, the other games could be mixed fairly easily.

With that in mind I like what you're doing here, I might mix up a few things (some equipment mostly), but otherwise I think this is great.

It's kind of obvious they weren't 'designed' to be fully compatible. And they're just using an updated system. FFG isn't intentionally or unintentionally trying to make it easier or harder to do cross-game things.

That disregards the fact people want compatibility entirely, which is why people are asking if it can be done, and if so, how?

In a way, what happens in 40k RPG can be likened to what happened with 3.x D&D under OGL. There were many systems that technically bore the mark of the OGL-compatible product, but you didn't really want to mix and match all of them, because many were built with vastly different assumptions.

With 40k, each game brings us some rule updates that can be adapted to previous iterations without much problem, but each game is also it's own beast with vastly different starting power level and scaling. The systems are similar enough that you can easily take any statblock from one and use it with another, but doing that indiscriminately will cause major fluff hickups due to different systems assigning different value and different costs to same pieces of rules.

Dark Heresy tends to stand out because FFG was much more conservative with many Talents and Traits in systems it designed from ground up than Black Industries was with it's first game, but it's not the sole culprit.

Generally, if you want to run "crossover games", it's better to decide upon one base system and then take some time to port whatever character types from other systems people want to play, ripping special rules from the appropriate system but building the career progression anew so that it fits in line with other characters from the base system assumed.

In light of this, Only War presents itself as easily the best basis for crossover games, because it's rank-less progression makes it very easy to write in other character types.

Aloha,

is there a conversion rule-set for Only War/Black Crusade to rogue trader?

I found nothing via search function. Maybe one of you guys have an idea where to look.

Thanks,

Sym

Please notice that all characters has access to the general aptitude.

Also a character can maximum get access to 2 of the non-characteristics aptitudes: Offence, Finesse, Defence, Psyker, Tech, Knowledge, Leadership, Fieldcraft and Social.

You can even see that if you get two of the same aptitudes from character creation, you must replace it with a characteristic aptitude, not one of those above (page 64 at the bottom):

"If, during creation, a character gains the same Aptitude
from different sources, he does not gain it twice. He may
instead choose an Aptitude that he does not already have and
that shares a name with a Characteristic. He gains the chosen
Aptitude instead."

This should be kept in mind when converting Dark Heresy careers to Only War specialties.

My sugestions for starting aptitudes on Dark Heresy careers:

Adept non-psyker: Knowledge, Social, Intelligence, Perception, Willpower, Fellowship, Agility
Adept psyker: Knowledge, Psyker, Intelligence, Perception, Willpower, Agility

Adepta Sororitas: Offence, Defence, Ballistic Skill, Weapon Skill, Perception, Willpower, Toughness
(if using blood of matyrs there is a lot of varity on this though)

Arbitrator: Defence, Leadership, Ballistic Skill, Toughness, Intelligence, Perception, Fellowship

Assassin: Finesse, Fieldcraft, Weapon Skill, Ballistic Skill, Agility, Perception, Intelligence

Scum: Fieldcraft, Social, Ballistic Skill, Agility, Fellowship, Perception, Willpower

Actually I would replace willpower with toughness for the Scum, but in DH scum payers heavy for toughness…

My sugestions for starting aptitudes on Dark Heresy careers:

Adept non-psyker: Knowledge, Social, Intelligence, Perception, Willpower, Fellowship, Agility
Adept psyker: Knowledge, Psyker, Intelligence, Perception, Willpower, Agility

Adepta Sororitas: Offence, Defence, Ballistic Skill, Weapon Skill, Perception, Willpower, Toughness
(if using blood of matyrs there is a lot of varity on this though)

Arbitrator: Defence, Leadership, Ballistic Skill, Toughness, Intelligence, Perception, Fellowship

Assassin: Finesse, Fieldcraft, Weapon Skill, Ballistic Skill, Agility, Perception, Intelligence

Scum: Fieldcraft, Social, Ballistic Skill, Agility, Fellowship, Perception, Toughness

Alox said:

Ratling has 3 non-Characteristic aptitudes: Fieldcraft, Finesse, Social.

Morangias said:

Some how I missed that, all the others only have 2.

The easiest way to convert for both DH and RT I found was to just look at the Stat Increase costs and give them the Aptitudes needed to match those costs. So if the career has a cheep Str increase it would have Strength and Offence aptitudes. This works out to a few oddballs in RT which is the system my group is converting over to OW's rules set but all in all it seems balanced enough for RT so far.