In Shadowrun 5th Edition, there is no Spirit Pact quality (research seems to indicate there was one for SR4). Is there anything in the rules that would explicitly prevent an SR5 character from starting with a Spirit Pact?
[RPG] Can you start the game with a spirit pact
character-creationshadowrun-sr5
Related Solutions
The major changes I noticed between the two editions are as follows:
Limits prevent characters from being overly min-maxed. Each of them is centered around an attribute that is typically dumped in normal characters; the most important attribute for the physical limit, for instance, is Strength, though other attributes weigh in they have the same impact as Strength does alone. This means that you can't build a "never gonna fight close quarters" build and just dump strength and expect to do well in other physical areas, encouraging a well-rounded thing.
Mystic adepts get a huge buff. I'm not exactly sure that this is a bad thing; they still can't astrally project, but they get the powers of both mages (other than astral) and phys-ads pretty nicely. Were they still using the BP system, this would be a flaw, and I'm not sure about allowing them as the third pick on your priority system, but I think the reason that people are upset is because they don't astrally project as much as they should when not a mystic adept.
The priority system really makes things a lot better. It prevents some of the worst cheesing during character creation (don't get me wrong-it's still possible, but you have to know what you're doing and make some sacrifices).
Combat's been changed rather heavily on the bookkeeping, but not so much the execution. The Accuracy limit keeps pistols from killing Great Dragons, which is a nice touch, but also discourages just dumping into the newly increased skills and maxing them out right away. It also makes smartlinks a more tangible advantage, as do laser sights. Armor is now a single rating for stun and physical, which makes it a lot easier for new players to understand, and, in my opinion, more realistic.
Hacking's a lot better. Mind you; the wireless thing contains some logic holes and gimmicks with the new benefits it gives stuff like cyberware or laser sights, but hackers can enjoy a target rich playground with new rules for hacking that make prepping a hacker 90% easier and playing one about 50% easier; GM'ing hacking also became a lot easier. In addition, some of the more broken technomancer stuff has been revised so you now have a reason to play a decker instead of a technomancer every single time.
All in all, it's faster and more streamlined. If you want my "reviewer" version, you can check it out on my blog, but I've said pretty much everything I said there here, only without the sales pitches.
Try 4th Edition's Augmentation
Augmentation may be for Fourth Edition, so you will need to do some minor conversions, but it does explicitly have a section on Advanced Wounds (much as 3rd Edition's Man and Machine did).
Limb Loss: The character is separated from his arm or another limb in a fashion that sprays blood everywhere. Arterial blood is under high pressure and can easily spurt up to 6 meters—be creative. The character suffers additional wound penalties and begins dying. The character begins taking additional damage as if from Physical Damage Overflow (p. 244, SR4) until stabi-lized. A transplant or cyberlimb replacement is in his future.
(Augmentation, p.121)
Note that there are specific situations for incoming damage which lead to this in-game, but the mechanic is pretty solid; you count as being bleeding out and you take more wound penalties.
Furthermore, there are rules for other nasty injuries in Augmentation, if you're interested. Of course, 5th Edition's combat guide is due out soon, so I don't know if I'd jump to the 4th Edition rules for injury right now (especially since there is some slight difference in the way damage works), but if you absolutely have to you can.
Best Answer
By RAW, you can't because there isn't a written rule that says you can. Spirit Pact has mechanical benefits, and there's no explicit way for a starting character to pay for them. They're meant to be gained in play, via in-character negotiation with powerful magical entities.
If you want to go beyond RAW, many of the Spirit Pacts are very powerful. You could look at the benefits and drawbacks of each pact and derive a cost. It's easiest if you're using Point Buy (Run Faster, p.64) because that gives you a single currency (Karma) to buy everything with, even things that normally take money.
Drain Pact is probably the easiest to adjudicate. It's vaguely similar to a Spellcasting Spell Focus (SR5, p.320) in that it grants bonus dice (albeit to Drain Resistance Tests rather than Spellcasting), but for all five types of spells. You could charge this one at the cost of all five Spellcasting Spell Focuses of a rating that matches the dice the spirit imparts. The character can't be deprived of it by any means other than the providing spirit, so it should be somewhat more expensive. However, in light of the included addiction, I wouldn't charge more (I wouldn't give back points for the Addiction, though.)
Dream Pact is depends on what the spirit does with the character's body when he's asleep. This particular pact doesn't really have any advantages for the character, only the spirit. You could model it with a variety of flaws, just with different reasons for having them:
...and that just covers the ones in SR5. Run Faster and other sourcebooks have others that may be appropriate.
Formula Pact is almost impossible to put a point value to. It has a very powerful benefit to the human (Immunity to Age). Combined with a Spirit Pact making both die (spirit and human) if either dies, the spirit has very strong motivation to watch out for the character. As a Formula Pact insulates a spirit from other uses of it's Spirit Formula, a Free Spirit likely make this pact as a defense against some other person or group that controlled it in the past. A Formula Pact is the focus of an entire campaign, not just a single character - all the player characters will get caught up in the backlash and blast radius of such a complication.
Life Pact is equally difficult to adjudicate. It is very powerful, and has no drawback for the spirit. The ability to directly spend Karma on healing (whatever the rate) eliminates much of the threat of combat.
Magic Pact is a bit more of a fair exchange for the spirit. Mechanically, it's very similar to a Power Focus, though it doesn't last nearly as long. How much it's worth depends on the GM; if the group gets hit with multiple heavy combat encounters in the same day, it's worth less. If it's only likely to be triggered once a day, it's worth more than a Power Focus, because it can't be lost, stolen, or misplaced. However you gauge the base cost, it should be reduced because the spirit can use up the human's Edge.
Power Pact is transitory, it only lasts 24 hours and has to be reactivated. I wouldn't even bother trying to establish a character-creation equivalency.
No matter how you adjudicate the magical abilities the spirit gives you, they absolutely must be taken as a Contact (SR5, p.98 and p.386). Free Spirits are powerful, so even if they don't have a lot of human connections, they should still have a high Connection rating. The nature of the relationship determines the Loyalty, as always.