BRP on Hârn - which magic system to use?

Hi everyone,

I'm thinking about using BRP to play a campaign in the Hârnmaster setting. I've noticed the "Beasts of Harn" document among the downloads, so I'm probably not the only one having this idea. The one thing I am unsure of is which magic system to use for the game. At this moment I'm leaning towards using the old magic system from Runequest 3rd edition (maybe using Sandy Peterson's rules for sorcery) along with BRP.

Has anybody tried this before? Which magic system would you recommend?

Thanks in advance!

You could just port the Magic and Religion systems for that authentic Harn feel. Since that might be too much work, though, I'd pick RuneQuest Sorcery for the Shek-P'var wizards, RQ Divine Magic for priests, BRP Psychic Powers for psionics, and MRQ2 Spirit Magic for shamans (if you use them). I don't see a role for Battle Magic / Common Magic / Folk Magic / RQ3 Spirit Magic unless you want to give wizards and priests some non-combat utility spells.

One problem with this lineup is that RQ Divine Magic is extremely powerful compared to the system in HarnMaster Religion, and conversely RQ Sorcery will seem weaker because it eats up so many MP. One alternative is to give priests Allegiance plus BRP/Elric Sorcery, although I'm not sure that does them justice either.

I have considered trying my hand at running HârnMaster at some point, and I am still undecided about the rules I will be using. Assuming I don't use the HârnMaster rules, I may run a HârnWorld campaign with straight BRP. In terms of magic, I have considered the following:

-For Shek-Pvar: the basic Magic rules from Big Gold (the Order of the Shek-Pvar would not be divided by convocations)

-For Psionics: Psychic Powers (who would have guessed?!?)

-For Priests: the basic Sorcery rules (just to give them something different. Still not sure if I would divide the Sorcery spells by religion or just resolve priest spells on a case-by-case basis)

Others may disagree with my choices for very good reasons. To be honest, unless I settle for the actual HârnMaster rules, I don't really intend to create an exact copy of the magic rules.

I would probably port over the Piety Points system straight from HM, because it is pretty easy to do and I am not sure how to apply the Allegiance rules to the Gods of Hârn. Ten different allegiances sounds like a lot more than the system can comfortably handle...

I am not really a fan of the RuneQuest magic rules, but I am mostly familiar with the first edition of the Mongoose version, and I do not know how it differs from older versions. My only other BRP resources are Call of Cthulhu, but obviously, the magic from that game has a pretty different feel...

I haven't looked there yet, but I am sure that the gentlefolk at the lythia.com forums would be glad to help!

Your method looks sound to me. I also ported Harn over to MRQ and BRP. I toyed with connecting certain Runes to Convocations, which actually worked quite well and was close enough for government work. I probably wouldn't bother so hard if I had it to do over though.

Okay I have to respond to this thread. There is an old out-of-print game called Maelstrom (set in 17th century England) which has an excellent magic system which is perfect for Hârn. Since you probably won't find the game around* I'll summarise the system here, including how I adapted it to BRP. I've used it successfully in Hârn and in my own Newhon campaign.

The Maelstrom magic system

There are no specific spells, just one generic Magic skill. Magic is situational and based on probability of an event occurring. When a mage wishes to cast a spell, the referee gives it a level of difficulty:

1. Probable. Things which might happen normally eg, a person tripping

2. Unlikely. Thing which could happen by accident but which are unlikely

3. Highly unlikely.

4. Wildly improbable. eg, crazy physical feats or strokes of incredible luck

5. Impossible in nature. eg, flying people, talking to dead men etc.

The mage rolls against his Magic skill - (10% x grade of spell) If he fails he can't remember the incantation and there is no effect. If he succeeds he makes a POW x5 roll for each grade of the spell. For each one that succeeds he loses 1D6 Magic Points; for each one that fails he loses 1 Magic Point. If all succeed the spell works.

That's the basics. This system works well in Hârn or any low-power or historical game for a number of reasons:

1. It is subtle. Did magic *really* happen or was it just a freak of nature/the will of the gods? Spell effects tend to be more 'natural-looking'.

2. It encourages tactical use of spells, and the same spells may vary in their difficulty depending on circumstances. A freak wave washing away your enemies would be Impossible (or at least Wildly Improbable) in the desert, but might be merely Unlikely on a rocky promontory by a stormy ocean.

You can vary the system by how expensive magic is to cast. There are also specialist mages who study a particular realm of influence (eg. fire magic) for whom the difficulty grade is reduced by one when casting spells related to their specialty. It is great little system which encourages cleverness, inventiveness and roleplaying (or at least tactics and positioning) from mage players.

* Actually it *is* being reprinted; there's a pdf available at Maelstrom - Arion Games | Maelstrom | RPGNow.com)

Questbird is wise and certainly the resident expert in using Maelstrom magic with BRP. Truly a subtle, powerful and flexible system.

Have you had a chance to look at the Maelstrom companion, QB? It's been on my list of things to pick up, but I haven't gotten around to it.

Have you had a chance to look at the Maelstrom companion, QB? It's been on my list of things to pick up, but I haven't gotten around to it.

I didn't even know about it. My reference all these years has been my dog-eared 1984 paperback edition of the game.

If he succeeds he makes a POW x5 roll for each grade of the spell. For each one that succeeds he loses 1D6 Magic Points; for each one that fails he loses 1 Magic Point. If all succeed the spell works.

I couldn't remember exactly how you did this part. I ended up tying up the POW rolls together as one roll. For difficulty 1 it was POWx5%, difficulty 2 was POWx4%, 3 was POWx3%, 4 was POWx2% and 5 was POWx1%. I wonder what the difference in probability is between the two methods?

I didn't even know about it. My reference all these years has been my dog-eared 1984 paperback edition of the game.

There are some Maelstrom fans and some Arion folk over at RPGNet. I heard about it over there. I think I haven't followed up on it because the original works so well. I would be interested in eventually taking a look at it though.

I couldn't remember exactly how you did this part. I ended up tying up the POW rolls together as one roll. For difficulty 1 it was POWx5%, difficulty 2 was POWx4%, 3 was POWx3%, 4 was POWx2% and 5 was POWx1%. I wonder what the difference in probability is between the two methods?

Hmm, a quite valid interpretation and fewer dice rolls required. Let's run those numbers with Aldo the Subnificent (POW 15):

First your method:

grade 1 - 75%

grade 2 - 60%

grade 3 - 45%

grade 4 - 30%

grade 5 - 15%

And then mine:

grade 1 - 75%

grade 2 - 75% x 75% = 56.25%

grade 3 - 75% x 75% x 75% = 42.19%

grade 4 - 75% x 75% x 75% x 75% = 31.64%

grade 5 - 75% x 75% x 75% x 75% x 75% = 23.73%

Interesting. Yours is slightly easier for the lower grade spells and mine is slightly easier for the higher grades. One advantage of the multi-roll system is the unknown and variable Magic Point cost (1D6 for successful, 1 point for failure) so the sorcerer never quite knows how draining a spell attempt will be. It's less mathematics but more dice rolling. You also feel like more of a champion if you get five Luck rolls in a row ;-)

yup, very true on the magic point issue. I think I tied to spell level xd6 where x equaled the level of spell attempted. I'd have to dig it up to be sure though.

But you're the one with the practical knowledge. I defer to your judgement on this.

Very ​interesting. I like this system a lot!

EDIT: Just bought both PDFs!

Sorry to necro this thread but I am fascinated by this idea for a free-from magic system.

My question is, how do you determine damage for something like say calling down a lightning strike on a foe?

Cheers!

19 hours ago, Celtic Viking said:

Sorry to necro this thread but I am fascinated by this idea for a free-from magic system.

My question is, how do you determine damage for something like say calling down a lightning strike on a foe?

Cheers!

A lightning strike called by this system would most likely happen during a natural thunderstorm at a high place, and in such circumstances I would rule it Probable or perhaps Unlikely (I think if the wizard had managed to get to high ground and wait for the storm I would say Probable, to throw him a bone). As for how much damage -- it would be the same as a natural lightning strike, which I don't think is modeled by rules. Some people survive them; some people die instantly. You could say something like 6D6 damage plus 2D6 if they're wearing metal armour. But that's just me ruling as if I were GM'ing it. Also a natural lightning strike could possibly be dangerous to others in the immediate area of the target.

That makes sense.

Would you let them pump "Power" into it to up their effects/damage or just rule that no matter how much POW they spend, lightning is as lightning does, etc...?

2 hours ago, Celtic Viking said:

That makes sense.

Would you let them pump "Power" into it to up their effects/damage or just rule that no matter how much POW they spend, lightning is as lightning does, etc...?

I wouldn't do it that way, but I suppose there are more powerful forms of lightning out there. So you could make the spell more unlikely (which would, coincidentally require more POW) to have a super-powerful lightning strike, or one which affected many targets, or particular targets only while sparing others. All of these effects are still 'possible' and therefore less difficult to cast than a grade 5 'impossible' spell.

Awesome!

Thanks for responding, I appreciate it.

If I think of anymore questions I'll jump in and ask them here.

Cheers!