Forgive the ignorance - how much of my home brew fantasy, that I am almost done editing, needs to be changed to not have to deal with the OGL?  I've been play testing for a year.  I was hoping to publish in March.

Specific points I wonder about.

1. Roll a d20 to hit and for skill checks

2. Using advantage and disadvantage

Most of the rest of my mechanics are very different. 

Mechanics per se are not protected by copyright, so the short answer is none.

There is a long complex answer to do with creative expression, eg don't copy somebody's text, not even to paraphrase. But I'm sleepy. 

1. WotC has a trademark on "d20" so I would avoid marketing your game as "a d20 game" since the ambiguity between being merely descriptive and impinging on a trademark is very fine there. But as a game mechanic (i.e. - "roll a d20 and add a modifier", etc.) is perfectly fine. Just be sure to keep all mention of "d20" as a reference to mechanics only and you should be safe.

2. Using Advantage and Disadvantage should be fine as well. However, look through the SRDv5.1 and see how it is described, then word your game sufficiently differently.

If those are the only two things you're worried about, I don't think you have anything to worry about at all.

Quote from: Vic99 on January 10, 2023, 06:46:11 PM
Forgive the ignorance - how much of my home brew fantasy, that I am almost done editing, needs to be changed to not have to deal with the OGL?  I've been play testing for a year.  I was hoping to publish in March.

Specific points I wonder about.

1. Roll a d20 to hit and for skill checks

2. Using advantage and disadvantage

Most of the rest of my mechanics are very different.

Mechanics are safe
D20 as a branding is a no-no since it's trademark of WotC
How much (if anything) did you take from their SRD (or paizo's)? Spells have to go, all the WotC monsters have to go (Beholder, Chromatic Dragons, Mind Flayers and the like) Mythological creatures (Dragons, Tiamat (as long as you don't describe her as a 5 headed multicolor dragon), elves, etc) are safe as long as you don't use WotC's fluff.

If you have Dark Elves and call them "Drow", that's too specific. 

If you have cave elves and call them some made up word like Dykrini, you're fine.  Or just the generic cave elves is fine.  I might go further and have Dykrini cave elves worship the moon or a Lava god, and not a female spider god. 

Stuff like that is what you need to worry about. 

Dice mechanics is NOT a worry.  Just like I can't copyright Texas Hold'em poker rules, or chess, WotC can't copyright 1D20, roll equal or over a target number.

I would change what certain terminology is used.  Strength, dexterity, constitution, intelligence, willpower, and charisma, and Armor Class.  I would get away from six by adding or subtracting an ability score, rename them as 5 or 7 "Attributes", call them Brawn, Agility, Toughness, IQ, Spirit, Charm, and a 7th called Speed.  Warriors wear armor, and have an Armor Category. 

This last part is only needed if you're paranoid.  I would do that myself, though.  I'm paranoid.

Geeky:
"Mechanics are safe
D20 as a branding is a no-no since it's trademark of WotC
How much (if anything) did you take from their SRD (or paizo's)? Spells have to go, all the WotC monsters have to go (Beholder, Chromatic Dragons, Mind Flayers and the like) Mythological creatures (Dragons, Tiamat (as long as you don't describe her as a 5 headed multicolor dragon), elves, etc) are safe as long as you don't use WotC's fluff."

I did not go to the SRD as part of my creative process.
You say "spells have to go".  I have a spell called "sleep", it puts creatures under 10 HP in a certain radius asleep.  Is that not generic enough?  I have "lightning bolt" it does different damage than D&D 3e or 5e, but  otherwise does what you might expect.

I use dwarf, elf, halfling, and human.  Might I have to change the name of "halfling"?

Weirdguy:  "This last part is only needed if you're paranoid.  I would do that myself, though.  I'm paranoid."

That's great.  Me too.  I actually have 7 attributes and the only one that is the same as D&D is Strength.

Quote from: Vic99 on January 10, 2023, 07:27:15 PM
Geeky:
"Mechanics are safe
D20 as a branding is a no-no since it's trademark of WotC
How much (if anything) did you take from their SRD (or paizo's)? Spells have to go, all the WotC monsters have to go (Beholder, Chromatic Dragons, Mind Flayers and the like) Mythological creatures (Dragons, Tiamat (as long as you don't describe her as a 5 headed multicolor dragon), elves, etc) are safe as long as you don't use WotC's fluff."

I did not go to the SRD as part of my creative process.
You say "spells have to go".  I have a spell called "sleep", it puts creatures under 10 HP in a certain radius asleep.  Is that not generic enough?  I have "lightning bolt" it does different damage than D&D 3e or 5e, but  otherwise does what you might expect.

I use dwarf, elf, halfling, and human.  Might I have to change the name of "halfling"?

I wouldn't risk it, so I would change it, mainly because I'm poor, not a lawyer and can't afford to consult one to be sure it's okay to do otherwise.

That being said: Sleep as a name shouyld be fine, as long as you don't have anymore similarities with their spell, same for "lightning bolt", check the descriptions in the SRD.

Halflings... Some say it's fine, some say it isn't... I wouldn't risk it, I changed it to Mitjan (middle in Catalan) a year ago because I like it better.

Avoiding using six attributes to not match them is as silly as using six attributes so as to match them.  It's irrelevant.  Now, if you use the same six, in the same order, and treat them about the same throughout, that's asking for trouble.  But as for the number, use the number that makes sense for the game, not one more, not one less.

Paranoid is one thing.  Deliberately putting in something unnecessary just because of paranoia hurts your game.

Steven M:

I agree.  I have seven attributes because that is what works for my game.

Quote from: Steven Mitchell on January 10, 2023, 07:37:17 PM
Avoiding using six attributes to not match them is as silly as using six attributes so as to match them.  It's irrelevant.  Now, if you use the same six, in the same order, and treat them about the same throughout, that's asking for trouble.  But as for the number, use the number that makes sense for the game, not one more, not one less.

Paranoid is one thing.  Deliberately putting in something unnecessary just because of paranoia hurts your game.

Agreed... Six attributes for my system works because it allows each to have about equal weight in terms of what each can do;

Strength - Lift/Carry, Climb/Jump/Swim Speed, most Melee Attacks
Endurance - Fitness skill checks, number of Reserves (and rate of Reserve recovery).
Reflexes - Acrobatics and Stealth skill checks, Initiative and most Ranged Attacks
Wits - Insight, Medicine and Nature skill checks + Mystic Spellcasting.
Intellect - Arcana, Culture and Engineering skill checks + Mechanist and Wizard Spellcasting.
Presence - Deceit, Intimidate and Persuade skill checks + Theurge Spellcasting.