   Free RPG rules for use in a game?
  I'm developing a 2d RPG, and I've come to the point when I should start writing the combat & character skills mechanics. I'd really like to use some already made system, because I think developing a custom system which deep and balanced enough would probably be very time-consuming. But I'm having difficulties finding such rulesets which I could use in my game (it's going to be freeware.) I took a look at GURPS Lite, and, although it's free, it still says in the license that "you may absolutely not use this in another product", which probably means I'm not allowed to use it even if my game is freeware.Do you happen to know any good free RPG rulesets I could use? Or would you suggest some other solution?Thanks for your answers!   
  Maybe the Open Game License is something for you: http://en.wikipedia.org/wiki/Open_Gaming_License;d20 v3.5 (but not 4.0) and Fudge are both OGL'd.   ;  Remember that technically you can use any rules you like. Rule systems aren't covered by copyright, only the written form of them is. Nobody can have a monopoly on what you might do when you roll a certain number with 2 dice, for example.Personally I would always recommend writing your own rules since most rulesets are biased towards a certain way of playing which won't necessarily fit your style of gameplay. But if you don't feel comfortable with statistics and probability, I suppose borrowing some other rules is better than nothing.   ;  To expand on what Kylotan said, you are safe using the mechanics of your favorite RPG, as long as you don't use the same terms and abbreviations, or only use generic terms. "Strength" and "level" are ok, but "Armor Class", "THAC0", and even "STR" or "Wisdom" can be problematic.Still, it may be a good idea to only use them as a base on top of which you build your own ideas. If you need help with numbers, you can post here or in the game design forum at RPG.net.   ;Quote:Original post by drakostard20 v3.5 (but not 4.0) and Fudge are both OGL'd.d20 3.5 cannot be used in software without the express permission of Wizards of the Coast. Check their clauses ;) That being said, if the mechanics are on the backend and not displayed to the user as the d20 system, then there wouldn't really be issue.;Quote:Original post by KylotanPersonally I would always recommend writing your own rules since most rulesets are biased towards a certain way of playing which won't necessarily fit your style of gameplay. But if you don't feel comfortable with statistics and probability, I suppose borrowing some other rules is better than nothing.To expound on this, consider the AD&D rules system:  it was designed to allow a Dungeon Master to intervene (bad roll at level 1 causes your character to get killed; a DM would step in and negate the roll, a game is going to let the roll stand and irritate the player), was not designed for "hack and slash" play (in Neverwinter Nights the XP gained for each creature was 10% of the actual value [could be wrong on the percent, but it's in that ballpark] because the characters advanced too quickly), and can make things difficult by attempting to implement the rules system without change (what do you mean I can't climb this pile of rocks with no enemies around because my climbing skill isn't high enough?  Given enough time, it should be possible!).  If you can find a copy of the original, 1st edition Dungeon Master's Guide Gary Gygax has a section on probability and dice rolls and how it all fits together.  It's an interesting read.;Quote:Original post by formalproofalthough it's free, it still says in the license that "you may absolutely not use this in another product", which probably means I'm not allowed to use it even if my game is freeware.Do you happen to know any good free RPG rulesets I could use? Or would you suggest some other solution?Yes you shouldn't use ruleset of someone else, and use theirs name. Otherwise you are completely free to use any numbers you want and any equation you want. (including any and all equation of said ruleset) Equations, or numbers can't be copyrighted.On the other hand you should definitely not copy these rulesets (even if you should be easily able to sidestep all law problems), you should educate yourself and create your own derivate. (and don't forget to honor tradition of the industry and ignore all people who would create a derivate of your system)Wisdom is a common word. Three letter abreviation is a common method in the industry. Armor class could have multiple meaning. A type of the armor. An efficiency of the armor. As in "a military armors are classed by number IV. So all armor class IV protections are military armors." (It's a common terminology in military.) A class where you are taught how to use armor in combat situation. As in "he skipped his armor classes, and now he fights as he would be naked. Luckily he didn't skip his weapon classes, so he didn't blow himself up."RPGs are often created by quite educated people, and use a quite old dictionaries. ~_^Do you know from where is a word drow?If someone loves suing other people and decide to act as jerk, you can't really stop him (without use of Mafia.).;Quote:Original post by KylotanRemember that technically you can use any rules you like. Rule systems aren't covered by copyright, only the written form of them is. Nobody can have a monopoly on what you might do when you roll a certain number with 2 dice, for example.But can't they be patented? I'm may be going out on a limb here, probably, but what about the Wizards of the Coast patent on tapping cards?Quote:Original post by ruby-langTo expand on what Kylotan said, you are safe using the mechanics of your favorite RPG, as long as you don't use the same terms and abbreviations, or only use generic terms. "Strength" and "level" are ok, but "Armor Class", "THAC0", and even "STR" or "Wisdom" can be problematic.Really? Something like Armor Class, STR, and Wisdom can be problematic in this situation? That..... sucks. But aren't there alot of games that uses that? STR atleast?   ;Quote:Original post by pothbBut can't they be patented? I'm may be going out on a limb here, probably, but what about the Wizards of the Coast patent on tapping cards?The implementation can be patented, if it is shown to be non-trivial, but not the mechanics. If, for example, you put a marker on a card instead of turning it to show it has been used this turn, you are no longer infringing the patent. In a computer game, you can simply shade the card to show it's been tapped.Quote:Original post by pothbReally? Something like Armor Class, STR, and Wisdom can be problematic in this situation? That..... sucks. But aren't there alot of games that uses that? STR atleast?It's borderline, but if you are using the d20 system with serial numbers filed off, this is the kind of thing a lawyer would look for. There is a STR stat in White Wolf RPGs, but it's a 1-5 scale. Steve Jackson's GURPS calls its 3-18 strength rating ST, besides using 3d6 instead of 1d20, and so on. Now if you use ratings that look like d20's, work like d20's and are named like d20's, you may receive a cease & desist letter. This doesn't mean it's illegal, and I'm not a lawyer to say what is and isn't legal anyway, but someone at WotC may decide to go after you.   