I just took a quick look at the psychic powers section in RT last night and wnated to share my thoughts:

The primary difference between RT's treatment of psychic powers and DH's treatment of psychic powers is in how they are activated. In DH you roll a number of dice equal to your psy rating to beat a power threshold. In RT you make a test against a specified characteristic (this appears to usually be willpower) and your psy rating acts as a bonus to your characteristic (+5 per rating)

This also allows for the RT mechanic for using powers with varying degrees of risk by alowing a psycher to restrain himself (use lower psy rating w/ less likely phenom/perils) or push (boost psy rating w/ greater chance of phenom/perils)

I'll have to go back an read to confirm, but I think that DoS on the characteristic test replaces Overbleed as well.

Overall I think the RT system is very cool and like the new aspects it opens up.

However, I do have one issue I'd like to hear addressed.

In DH the powers having different thresholds meant that certain powers were harder to use than others. This made sense as some powers were more powerful than others. Some were even big enough that if you did not have sufficient psy rating you couldn't do them at all. As you got more dice from your psy rating you became more able to use the bigger powers more an more easily, but regardless it was always easier to use a weaker power than a stronger one.

Now I haven't had a chance to read the individual RT psychic techniques, but at a glance it seems that all powers are based on roll vs. characteristic + psy rating (or other) modifiers. As a result, for a given individual psyker power A and power B (presuming they both use the same characteristic) are always the same difficulty to use. So unless all the powers are basically equivalent, or some of them impose a penalty just b/c they're more difficult, this seems kind of screwy to me.

I ran into this issue particulalry b/c I was wanted to swap all my psykers to one game mechanic and was trying to figure out translation of threshold difficulty to the RT version.

Can someone enlighten me on this?

I've given my opinion in another thread that the two systems are definitely different, but I think they each work for their respective games. (Though the RT one is IMHO not as well organized as it could be.) There are a lot of RT things I see myself in time swiping for my DH game, but frankly the psyker rules isn't one of them.

I had assumed that rather than trying to balance relative power strength based on difficulty threshold, they were balancing it based on the XP cost to acquire it (which therefore also indirectly relates to how soon you can take it). Therefore, if looking to convert DH-RT you probably want to have a correlation between threshold and XP cost.

There are also a few powers that cannot be used at Fettered Strength, also representing an additional level of difficulty in pulling them off.

Yeah I had noticed the XP thing. And different powers having different costs is good, but doesn't solve the problem in my mind. It just seems off somehow that the difficulty of lighting a candle and the difficulty of erasing someone's brain would be the same.

DocIII said:

I can't really argue with that. Again, that's part of why I'd be unlikely to try to combine or port the systems. They (this is all my interpretation, not quoted from a panel or anything) left out the minor powers and even some of the less impressive regular powers in RT. It seems to me like the RT system was built around the assumption you're always trying to erase someone's brain, not light a candle.

What I think I may do is play with numbers a bit and then say:

DH powers with thresholds from 1-X are no modifier to the characteristic test, powers with threshold X-Y are at -10, powers with threshold Y-Z are -20 and so on. I'll have to sit down and crunch numbers to work out the ranges. That way the different degrees of inherent difficulty of use of DH powers is preserved.

In the case of some of the minor powers/lower thresholds a bonus may even be warranted.

Of course to make that work well I'll have to look close at the RT powers and decide if I think modifiers are warranted there as well, but all in all it should be a reasonably simple fix.

Now i havn't seen thr RT book but i would have thought that there was a different system for psykers because the psykers in RT (Astropaths and Navigators) are very different to Sanctioned Psykers. The Systems wern't designed to be compatible because well...theres no need for them to be. An Astropath or Navigator are going to have different powers to a Sanctioned Psyker. In the design diaries it states that RT psykers access the warp in different ways

Talex,

RT specifically says in a sidebar the two are designed to be two different rule sets on the same idea. In fact almost all the RT powers are very close to powers that have appeared somewhere in DH.

Like i said i havn't seen the book. (living in the UK makes it hard to get to america) I suppose i should really shut up as i havn't seen it, Ignorance being the Voice of stupiduty but hey, i'm bored

DocIII said:

You know, it's funny. I had come up with house rules for psychic powers that worked exactly like this. Never had the chance to test them because none of my players have the guts to play a psyker.

I worked out the following difficulty modifiers for psychic powers based on threshold:

Threshold 5-8 (+10)
Threshold 9-14 (+0)
Threshold 15-20 (-10)
Threshold 21-26 (-20)
Threshold 27+ (-30)

Ok, so let me get this straight...

Say my WP is 30 and my Psy rating is 3.

I roll a d100 and add +15 and the target number to beat is 30?

Hmmm....

Seems to me the target number should be based on the power , not the characteristic.

For example:

Ball of Abysmal Flame had a threshold of 26 (don't bust my chops, I'm making this up. I know BoAF is an Ars Magica spell...) Translate that over adding 20 (Lucius' example) for a target number of 46.

I roll d100, add my WP and +5 per Psy Rating. No, too much variation... OK< d10+WP+(5xPSY) so the range would be 46 to 54 Degrees of Success could translate to "Overbleed" etc. etc.

that way throwing a fireball would be a lot harder than lighting a candle and lighting a candle would be very trivial...as it should be.

What do you think?

No, I don't think that's it at all. What I'm hearing is that psychic tests in RT work just like every other test.

So, if you have WP 30 a Psy Rating 3, you need to roll a 45 or less to successfully activate a power. Now, I don't have RT but that's how it sounds to me.

My addition is to include a difficulty for each power, so that what in DH is a threshold 26 power would impose a -20 on the check... requiring our WP 30, Psy 3 psyker to roll a 25 or less.

LuciusT said:

I can see the conundrum of every power being the same difficulty. Well, we can't have that in our game!

I like your idea and I'll try it.

My idea simplified is: each power has a rating. Roll d10+WP bonus+Psy rating, beat the target power's rating to successfully activate.

Non-simplified is d100+WP+(5xPsy) and beat the target power's rating. Obviously, the power rating would be higher. Essentially the same thing, but this would lead to more near-misses and barely-made-it's and also allows for more variable GM modifiers and differentiations in power difficulties.

Basically, the higher the target rating (which should fairly easily translate from DH's difficulties) the harder it would be to activate. The higher your WP+Psy Rating, the more powers become trivial for you.

So, I'll try all the systems and see which works best for my group.

Man, I wish I had the RT book...soon....My Precious....

How does Invocation work into all of this, or has it been cut entirely?

I'm going to have to go back and look on the invocation question.

The base conundrum here is that the basic mechanic for triggering psychic powers is different between DH and RT

In DH you roll a number of dice equal to or less than your psy rating, total them add you Willpower bonus and any other appropriate bonuses then compare the total to the power threshold of the power you're trying to use. Powers have thresholds ranging from 6 to 30+

In RT you test against a characteristic (usually Willpower) +5 for every point of effective psy rating. If you succeed on the test the power works. Like all other characteristic tests this is a percentile roll trying to get under your characteristic plus modifiers (i.e. modifiers are added to the score you're trying to roll under, not to the dice themselves)

As a result in DH some powers are harder than others to do. In RT some powers cost more XP than others, but all just roll against the same thing (characteristic + psy rating x 5 + other modifiers).

So in porting over DH powers to use the RT paradigm (which I like better, at least on paper, will have to playtest to tell for sure) I wanted to do something to preserve the element that some powers (usually weaker ones) are easier to use than others (usually stronger ones).

So what I'm going test out is this for using DH powers under the RT psyker rules:

DH Threshold / RT Characteristic test modifier :
< 10 / +20
10-14 / +10
15-19 / +0
20-24 / -10
25+ / -20

Powers w/ overbleed - use DoS on chracteristic test to determine amount of overbleed.

Also I intend to allow RT psykers (Astropaths, etc.) to take minor powers in the same manner as DH Sanctioned psykers.

Looks good to me. That all psychic powers are equally easy to manifest in Rogue Trader doesn't sit right with me, and I say that with all the authority of someone who hasn't read the rulebook yet.

What triggers psychic phenomena in RT ?

The roll of a double (33, 55, 88 and so on). Or so I've been told.

Phenomena occur differently depending on how you manifest the power.

If you manifest at a fettered power level then no phenomena

If you manifest at unfettered then phenomena on roll of doubles

If you Push then phenomena always occur.

Before you guys figure out how to "improve" the RT psyker system, think of a few things. Astropaths are "professional" psykers - the "don't try this at home" kinda guys who do all sorts of things with the greatest of ease.

Whereas a DH psyker will find it easier or harder to use a given power depending on what it is, an RT astropath just needs to decide how hard s/he wants to try. Many of the effects depend on your (effective) psy rating, so if you use your fettered strength, the power is weaker... In addition, there are some stiff prerequisites for the stronger powers (ie psy rating of X AND power A AND power B).

I quite like both systems, but the RT system reflects the strength, training, and reliability of an astropath - which I like quite a bit.

Cervantes3773 said:

In wouldn't say that Astropaths are the Professionals while Sanctioned are Armature Hour. After all, Astropaths were weaker then sanctioned psykers, not the smoother cooler guys sanctioned psykers wished they could be. They had a weaker will which mandated them being soulbound to the Emperor to still be of use to the Imperium unlike sanctioned psykers who had the strength of will to forge ahead with their eyes intact and their soul still quite firmly their own. The greater (yet more limited) power they have as well as greater control comes from the Emperor, not them.

Cervantes3773 said:

Umm... Astropaths are weaker, less well trained and more unreliable than sanctioned psykers. They're the second tier, strong enough to be useful but not strong enough to function on their own without safeguards. Sanctioned psykers are the first tier, strong enough in both power and will to handle their powers with relative safety.

Yes the soul binding is performed on them because they AREN'T awesome and will not survive as a psyker without it. Primary, Secondary and Tertiary psykers. Primary are the ones allowed to wander around under their own free will whilst astropaths are secondary and those fed to the emperor tertiary.

Hellebore

Also, the RT psyker section clearly says that the systems therein are for all psykers in RT not just astropaths. If these rules were just for astropaths there would not be a separate sorcerer/renegade psyker column on the table describing chance of phenomena at different invocation strengths.

That being said, I guess the GM is at liberty to pick and choose which system he/she likes and Biblically interpret the grey areas. But that's always been the case, hasn't it?

LuciusT said:

If this is the case (and I'm not sure it is--don't know where its from) its certainly not the case universally. There is a sidebar in the RT Psychic chapter discussing the implications of Astro-telepathy on the edges of space, where the game will frequently be. Exceptional astropaths arise in those conditions who are of unquestionable mental fortitude. They are called "Astropaths Transcendant". You might also note this is the full name of the Astropath class.