OGL CRPG implementation issues

[BigWeather]

I read in another thread (I think on here, but to be honest it could have been on RPG.net) that creating an OGL-based CRPG would be virtually impossible due to not being able to meet the terms of the OGL. The thread mentioned the existence of a long discussion on ogf-l about it but my Google Fu is weak and I haven't found it. Having read through the OGL, and given the existence of a newly released OGL-based CRPG (Knights of the Chalice), I'm wondering if it is doable. If so, I'm very tempted to try my hand at a CRPG based on the Pathfinder RPG Reference Document -- not only because I'd love to play such a game but it is an excellent way to really learn the ruleset!

According to the OGL at d20 System Archive and the Software and OGL FAQs all that should need to be done is:

1. Make the OGL viewable to the consumer

I'm assuming that an in-game display of it (through Help & Options, Credits, Extras, or the like) and in addition (for a PC game) a stand-alone human-readable text file would suffice?

2. Update Section 15 of the OGL to include any additional copyright information

I'd update it to point to the Pathfinder RPG Reference Document and anything it does. This includes the SRD, Tome of Horrors, and some other stuff. In the case of the Tome of Horrors (which I don't own) I assume I'm responsible for chasing down its Section 15 so that I can bring it into my OGL Section 15? What to do in the case that the work is no longer available? Has someone been compiling Section 15s of various works that may leave print online somewhere?

3. Clearly identify and display Open Content

This is the hardest one, I think. Is it sufficient to have an in-game display of the rules, etc. (similar to the OGL above, from a menu option)?

Is it necessary to have the actual parts of the game, as it is running, that use Open Content clearly identifiable and linked back to the in-game Open Content browser?

As an example, if my text box has "<Character name> swings at the wraith and misses (roll was 18, required was 19)" do I have to indicate that that text line is the result of Open Content in the background (i.e., the rules running)? If so, can I just bold / italicize it? Is it necessary to have the consumer able to click on that line and it take them to the relevant Open Content sections in the Help?

Combat is an obvious thing that can be tagged as Open Content and linked to the rules in the Open Content section in the Help. How about something like movement that is likely not logged for player consumption (due to spam) but has mechanics dictated by Open Content (limitations on movement by race, for example)?

Finally, consider the following from the Pathfinder RPG Reference Document concerning Attack Roll and Attack Bonus:

"Attack Bonus

Your attack bonus with a melee weapon is the following:
Base attack bonus + Strength modifier + size modifier

With a ranged weapon, your attack bonus is the following:
Base attack bonus + Dexterity modifier + size modifier + range penalty"

Is it sufficient to just have the above text in my help files (possibly linked to by individual combat messages in the log)? Or does it have to be in a form that not only humans can consume but so can the game's engine. E.g.,

"<AttackBonus>
<OC_Description>Your attack bonus with a melee weapon is the following:
Base attack bonus + Strength modifier + size modifier

With a ranged weapon, your attack bonus is the following:
Base attack bonus + Dexterity modifier + size modifier + range penalty</OC_Description>
<Melee>player.BAB + modifier(player.STR) + modifier(player.size)</Melee>
<Range>player.BAB + modifier(player.DEX) + modifier(player.size) + rangePenalty(target.distance)</Range>
</AttackBonus>"

I guess it is the OGL FAQs statement "...you have to give all the recipients the right to extract and use any Open Game Content you've included in your application..." that is tripping me up. As a programmer "extract" brings to mind a lot of things like having to make the data available in a form that could then be imported into another application. This would dictate that the game engine parses all Open Content rules, etc. from something like the XML above and someone else could write a similar engine (which of course isn't Open Content) that parses and executes the formulas.

A later statement in that same answer, however, leads me to believe I'm over-thinking it: "One way is to design your application so that all the Open Game Content resides in files that are human-readable (that is, in a format that can be opened and understood by a reasonable person). Another is to have all the data used by the program viewable somehow while the program runs."

That seems to be a looser definition that would allow me to make all Open Content available through the Help & Options menu or something (as well as link to it where applicable when the game is running). For a PC version the Open Content could also be made available as files in the installed directory. Closed platforms like the 360, iPhone, etc. wouldn't allow this, though.

Of course the reference to "data used by the program" trips me up as a programmer: the melee attack bonus formula is not data, it is metadata -- the data are the actual numbers plugged into the formula. I'm assuming again that I'm over-thinking this and it is sufficient to just say "hey, my game uses Open Content. That Open Content includes the melee attack bonus formula, which is as follows" in the Help file displayed from within the game.

I'm assuming only the portions of the Pathfinder RPG Reference Document I use would need to be viewable, correct (for example, not using spells in a no-magic setting). Though even if I don't use the pieces that happened to come from the Tome of Horrors I am still responsible for reproducing their copyright in Section 15, I'd imagine.

In summary (and thank you very much for reading this very long first post!), I'm planning on doing the following and hope it is sufficient to satisfy OGL terms. If it isn't I'll find a way to make it work.

1. Make the OGL viewable from within the game (and additionally a separate file for PCs).
2. Update Section 15 of the OGL to contain appropriate references.
3. Make the Open Content used by the game viewable from within the game as human-readable help text (and additionally a separate file for PCs).

I'm thinking I don't need to do the following:

1. Have the actual rules (formulas) in a human-readable and machine-parseable form that the game engine reads and runs. I'm hoping stating that I use the Open Content Attack Bonus rule and allowing the consumer to view it within the game is enough for them to trust that yes, the code is running those rules.
2. Link every single game action to Open Content. Where feasible I will (like being able to get details on how results in the combat log were generated) but it seems that some cases (like simple movement that isn't otherwise logged) aren't possible.

Lastly, if anyone does have a pointer to that epic thread about OGL CRPG implementation difficulties I'd appreciate a link. Thanks!

 

[afstanton]

I'd suggest browsing the source code and datasets for PCGen for examples of how this might be done. It's under the LGPL, so you may even be able to use it as part of your project.

 

[Nylanfs]

Preface INAL.

What they were refering to was the using the d20 license for a computer game, which eliminated random generated numbers (which hobbled almost any program almost entirely). Using the OGL you can make essentially any game you would want to.

You have all the right information, and are on the right track. You really only have to provide information back to the user if you are creating "original" data as opposed to using existing data from another source. Ie the SRD, the Pathfinder book, any of their third party books. (Note I state user). And you have to update your Sec. 15 of the OGL to include ALL the references AS printed in the source data's Sec. 15 (except you can clip out duplicate entries ie. only one citation of the SRD is needed)

To comply fully with the OGL you have to provide some type of data file that other publishers can use whether that be XML, or plain text like we do at PCGen. But that is the data that you are feading into your program it's NOT the mechanics nore the derived data from said mechanics. Just what data you are using to drive the metadata.

 

[BigWeather]

Preface INAL.

What they were refering to was the using the d20 license for a computer game, which eliminated random generated numbers (which hobbled almost any program almost entirely). Using the OGL you can make essentially any game you would want to.

Ah, OK. Yeah no intention of doing d20 licensing.

You have all the right information, and are on the right track. You really only have to provide information back to the user if you are creating "original" data as opposed to using existing data from another source. Ie the SRD, the Pathfinder book, any of their third party books. (Note I state user). And you have to update your Sec. 15 of the OGL to include ALL the references AS printed in the source data's Sec. 15 (except you can clip out duplicate entries ie. only one citation of the SRD is needed)

So I need only document to the user any additions to the Open Game Content (and declare those additions open or not, I suppose)? Any Open Game Content that I use (the stuff referred to in Section 15) needn't be documented to fulfill the terms of the OGL (though, clearly, there are other reasons to document the rules for the user)?

As far as updating Section 15 -- the Pathfinder RPG reference refers to Tome of Horrors. Suppose that I couldn't get a copy of the Tome of Horrors; how can I then figure out what their Section 15 used so that I can roll it into mine? I guess that is what Internet message boards are for, but it'd be great if there were a repository of products' Section 15s somewhere. This could become a real issue going forward as products, particularly the more obscure ones, leave print and become very hard to locate.

To comply fully with the OGL you have to provide some type of data file that other publishers can use whether that be XML, or plain text like we do at PCGen. But that is the data that you are feading into your program it's NOT the mechanics nore the derived data from said mechanics. Just what data you are using to drive the metadata.

Is this data only my additions to the existing Open Game Content or does it also include existing Open Game Content data? Does that clause preclude implementation on consoles or other hardware that don't allow file system access? I'm hoping that displaying the data, even in XML form on-screen, is sufficient for those platforms.

Thanks again for the response (and the one above it, as well, thanks!) -- and of course I understand the INAL qualifier. It is great to hear about your treatment of the OGL, however, as a publisher of electronic product based on it.

 

[Guillaume]

As far as updating Section 15 -- the Pathfinder RPG reference refers to Tome of Horrors. Suppose that I couldn't get a copy of the Tome of Horrors; how can I then figure out what their Section 15 used so that I can roll it into mine? I guess that is what Internet message boards are for, but it'd be great if there were a repository of products' Section 15s somewhere. This could become a real issue going forward as products, particularly the more obscure ones, leave print and become very hard to locate.

While the Tome of Horrors hardcover has been out of print for a few years, the book itself is still available in pdf form. You can buy a copy from ENWorld/RPGNOW pdf store. The original 3.0 version is available for 11.98 USD. The revised version for 3.5 is also available for 7.99 USD.

 

[Nylanfs]

Ah, OK. Yeah no intention of doing d20 licensing.



So I need only document to the user any additions to the Open Game Content (and declare those additions open or not, I suppose)? Any Open Game Content that I use (the stuff referred to in Section 15) needn't be documented to fulfill the terms of the OGL (though, clearly, there are other reasons to document the rules for the user)?

As far as updating Section 15 -- the Pathfinder RPG reference refers to Tome of Horrors. Suppose that I couldn't get a copy of the Tome of Horrors; how can I then figure out what their Section 15 used so that I can roll it into mine? I guess that is what Internet message boards are for, but it'd be great if there were a repository of products' Section 15s somewhere. This could become a real issue going forward as products, particularly the more obscure ones, leave print and become very hard to locate.

You don't have to worry about labeling what OGC material THEY used. Only what you used. Yes This means that nobody knows what everyone else is using, it's a pain. But it's too late at this point to get everyone to start labeling exact OGC they used from another publisher.

Is this data only my additions to the existing Open Game Content or does it also include existing Open Game Content data? Does that clause preclude implementation on consoles or other hardware that don't allow file system access? I'm hoping that displaying the data, even in XML form on-screen, is sufficient for those platforms.

Since you are doing a translative derivative you should to provide the all of data that is driving your program in human readable terms, XML is fine. Which is why you should separate your code and your data entirely.

Thanks again for the response (and the one above it, as well, thanks!) -- and of course I understand the INAL qualifier. It is great to hear about your treatment of the OGL, however, as a publisher of electronic product based on it.

NP