Backwards compatibility: what does it mean and how far does it go?

[Roger Bert]

Greetings.

I am interested in Pathfinder as way to stick with a 3.5 similar game and still be able to get some ‘store bought’ scenarios. I very much like D&D 3.5 and consider it probably the best version of D&D ever but I do admit it has flaws. The more compatible with v3.5 that Pathfinder ultimately ends up as the more likely I would purchase scenarios from your company.

One of my players at last Saturday’s session had to leave unexpectedly. So as a test I printed out Pathfinder character sheets and had everyone convert their current characters as best as we could just to see how it worked out.

No one minded that fact that there were extra class abilities. No one minded the fact that most of the characters gained hit points. Only one person disliked the new skill system but everyone else was fine with it including myself as a Dungeon Master. Would be much quicker generating NPC skills with this system. Everyone was happy with the extra feats they received and we actually use some home rules where new characters gain an extra feat more than usual at 1st level anyway. None of these aspects were seen to me as a Dungeon Master as compatibility issues with existing rulebooks or scenarios. It would be easy to fix this stuff even on the fly.

Problems we all disliked rather strongly:
1. Changing existing feats
2. Changing existing spells.

We all had our fill of this when we switched from 3.0 to 3.5 and even to the Rules Compendium (for some spells anyway, kind of like a 3.6).

I strongly suggest that changing existing feats and spells should be extremely limited. I imagine most people looking at Pathfinder are going to want to be able to use existing prestige classes in complete splatbooks and other OGL products and other existing spells. I think everyone notices that all the new Official D&D classes have more power than the original 13 in general and that boosting PHB classes is ok and converting material would require minimal work. Converting modules and other material where most feat chains have been changed and lots of spells changed is a lot more work. It is easy to add a few more hit points and a bonus feat here and there but far more difficult to rebuild whole feat structures of NPCs and redo whole spell books of an NPC sorcerer who should die in 5 rounds or less. I don’t want to spend an hour redoing his spells for 5 rounds or less.

Compatibility is the most important aspect for me.
Thanks.

[GVDammerung]

“Backwards compatibility.” Note that the term has two components.

“Compatibility” refers to a mutually sympathetic/utilitarian relationship between X and Y states. X is in sympathy with Y, and Y is equally in sympathy with X. X can be utilized with Y, and Y can be equally utilized with X. Compatibility is covalent. Covalence does not require absolute similarity or compatibility as between X and Y. Rather, X and Y need only share a sufficient relationship to be mutually sympathetic/utilitarian.

“Backwards” defines the Y state. The X state is that of the present/future. Or vise versa if you prefer. Distinctions between “backwards compatibility” and “future compatibility” miss the point of covalence and are irrelevant. As between X and Y, covalence exists and effects each state in an equivalent fashion or it does not exist.

P3 (the Pathfinder RPG) and 3.5 D&D will be backwards compatible if their relationship is covalent. P3 characters should be able to function pretty much “as is” in a 3.5 adventure; 3.5 characters should be able to function pretty much “as is” in a P3 adventure. Similarly, P3 monsters should be able to be used pretty much “as is” with 3.5 characters, and 3.5 monsters should be pretty much able to be used “as is” with P3 characters. The same relationship should hold for magic spells, feats, skills etc. Note the use of the phrasing “pretty much.”

Covalence does not demand absolute identity between X and Y. It only requires a critical sharing of elements sufficient for a mutual sympathy/utility. Hence, “pretty much” the same does not invalidate the compatibility.

Practically, this means P3 can, and indeed must, differ from 3.5. P3 can, in fact, vary substantially from 3.5, and still be backwards compatible as between P3 and 3.5 so long as the relationship between the two remains covalent.

Doing away with hit points, Vancian magic etc. would destroy covalence and are thus nonstarters in P3 design. Giving a particular class a set of variant abilities does not necessarily destroy covalence. Changing how grappling works does not necessarily destroy covalence. The devil is in the details.

“How far” is “too far” to retain covalence is, I think, a function of magnitude. Hit points and Vancian magic, for example, are everywhere in D&D, both pervading the game and helping to establish is defining characteristics. They are of such magnitude within the game that changing them would destroy the covalent relationship between any new game and 3.5. Grappling is of a lesser magnitude and is then more amenable to tinkering.

The danger is this - there are a number of low magnitude elements of 3.5 that each could be modified without impacting covalence individually. However, if one sufficiently modified _enough_ of these smaller magnitude elements they might add up to a sufficient degree of difference to destroy covalence. Death by a thousand cuts in other words. Paizo has to be particularly careful in this regard.

There is the danger of an accumulation of small changes adding up to a change factor big enough to destroy covalence both objectively and subjectively. The foregoing has looked at objective rules functionality. The subjective factor is independent and is solely the function of how people will “feel” about P3 as it relates to 3.5. Even if P3 is objectively compatible with 3.5, if people subjectively feel it is not covalent, not backward compatible, Paizo is in just as much trouble as if P3 were objectively incompatible.

It is Paizo’s task to manage both the objective and subjective aspects of backwards compatibility. I trust they are aware of this and will do so.

There is an old saying “measure twice, cut once.” Paizo’s open playtest is measuring twice. The Alpha, then Beta versions, before the finalized version is another example of this. Paizo’s goal is to get it right when the final cut is made. Given this cautious approach of measuring twice, no one should prejudge the final P3 until it is final. Playtests are all about testing possibilities and seeing what works best with what. Those who contribute ideas that are not adopted contribute just as much as those whose ideas are adopted. Its all about giving all the ideas an exploration and putting together those ideas which work best together. Those already suspicious of backwards compatibility are leaping head in their thinking to 2009. Paizo is working in 2008. The future is now.

[Swordslinger]

Backwards compatibility to me is the idea that you can basically still run older adventures without changing a heck of a lot of stat blocks and such.

So you don't run into a creature that has the fireball spell and realize that there isn't a fireball spell or that the wildshape class ability no longer exists.

Now, while that seems limiting, it's honestly not, because you get to change the descriptions and utility of those abilities. So while some NPC fighter may have had the spring attack feat, that feat can do something entirely different if we wanted it to. Spells of course are entirely malleable. So acid arrow need not suck anymore, and we can fix the broken polymorph mechanics.

Really just about the only thing that you can't do while maintaining BC is add a lot of class abilities or remove any abilities or spells. But you can modify combat rules, change spell descriptions and all manner of useful balance changes that make the edition worthwhile.

[Tamago]

I agree with the above. For me, as a DM, backwards compatibility mostly means being able to run prewritten adventures without conversion. I'm willing to put a little more effort into figuring out how the niggly bits of other sourcebooks fit into things if one of my players wants to take something from there, but I should be able to take a statted-up 3.5 NPC from a book and run him without having to do anything.

Where I think the new edition can really shine is in changing some of the "game engine". For example, if I have a character try to bull rush someone, it doesn't matter if that character was originally written for Pathfinder or 3.5 -- I can use the new Bull Rush mechanic and things work beautifully. It's the "behind the scenes" stuff that mostly needs changing anyway.

For example, consider spells: I would advocate confining changes to the spell descriptions, rather than messing around with what level a certain spell is, or how many spells per day a character gets. Then, I can take an NPC spellcaster from Module X and run him, substituting the new spell effect on the fly.

[Swordslinger]

Tamago wrote:

For example, consider spells: I would advocate confining changes to the spell descriptions, rather than messing around with what level a certain spell is, or how many spells per day a character gets. Then, I can take an NPC spellcaster from Module X and run him, substituting the new spell effect on the fly.

Right, can't really change around a spell's level at all, but you can basically do anything you want to the spell description (which should be enough versatility to balance whatever needs to be balanced).

[Brom Blackforge]

GVDammerung wrote:

P3 (the Pathfinder RPG) and 3.5 D&D will be backwards compatible if their relationship is covalent. P3 characters should be able to function pretty much “as is” in a 3.5 adventure; 3.5 characters should be able to function pretty much “as is” in a P3 adventure. Similarly, P3 monsters should be able to be used pretty much “as is” with 3.5 characters, and 3.5 monsters should be pretty much able to be used “as is” with P3 characters. The same relationship should hold for magic spells, feats, skills etc. Note the use of the phrasing “pretty much.”

I'm going to nitpick a bit and say that you shouldn't need the "pretty much" in there. You should be able to pick up a 3.5 adventure and run it in your PRPG game without changing anything. Your players' PRPG PCs should be able to rub shoulders with the 3.5 NPCs without any tinkering necessary. THAT would be backwards compatible.

I may be putting myself in the minority here, but I don't feel like there is any need for big changes to 3.5. I don't really want to see things totally reworked. And I'd like to find that PRPG characters are roughly equivalent to 3.5 characters; I'd hate to see PRPG as just another notch on the power creep scale.

Maybe Paizo wants to have sufficient changes to justify players plunking down their hard-earned cash for the finished product. I can understand that. But I see a fine line between enough changes and too many - because if using PRPG requires extensive adaptation and tinkering to use my 3.5 material, then I'll just skip it and keep playing 3.5.

[Neithan]

So, I dig it up again, too:

Though I like many of the new ideas, I think many of them are not needed (personal opinion). Which is okay, but is there an "official" statement about the goals and specific intent of "compatibility" regarding the PF innovations?

Currently it appears to me as a great source of a lot of cool optional rules for my 3.5e game, but I'd like to get a more clearer idea about what to expect of the whole thing.

[Dread]

I think Paizo is on the right track with their idea. The playtests, the Forums, The Feedback. All of this is indicative to me of them trying to get it right.

Pathfinder needs to be diferent enough to 'set themselves apart' once the final product is released. Yet need not be so diferent as to change core mechanics. Familiar yet diferent, should be the credo. Yet I echo the sentiment, 'If it isnt broken, don't fix it'

I like 90% of what I see...I hope that anything that is drastically diferent gets relegated to an option instead of core. An example of this would be altering the initial hit points too much. in otherwords, doubling would be optional...adding in a racial bonus would be fine.

[Trojan Dwarf]

One of the most important things to remember, IMHO (it really is not that H) is this is the Alpha Test and as things are tested and feedback is delivered, the Beta will be formed. The Beta will be closer to what will eventually develope into the final product. So far, my playtesting of STAP has worked well. The players are really enjoying the changes and feel that they have been brought up to par with some of the "newer" core classes. Also, the Paizo adventures are writen for a braod audience and can be rather lethal to the non-munchkin or cheeseless players. 4 out of 6 fo my players are conceptual role players. They develop a PC idea a follow through with it to the end (bloody or otherwise). Of the other two, one is a mini-maxer and the other is a cheese-lovin' munchkin of the first caliber. I know this and deal with accordingly. The changes to PRPG is appealing to all of the players. They feel that they are on equal footing with the two power gamers. Also, they have a greater chance of surviving the evils that Paizo wrought.