I was wondering if anyone has implemented Luck and Karma rules successfully. I was considering adopting both in a "homebrew" style which I was inspired from other online wikis.

I was thinking... the group each have a starting stat of 10 luck/karma, as they do good things they gain luck/karma or they do bad things which decreases it. Think of Karma as the modifier to luck. Throughout the game I will have a "test your luck/karma" system or the player can choose to test it themselves.

I ask them to roll a d20 

If they succeed, it turns: -  a success skill check to a maximum success or a failed skill check to a success.

If they fail, it turns: - a success skill check to fail or a failed skill check to a maximum fail. 

If they want to test their luck they need to roll a d20. If the number they rolled is lower than their luck, they succeed, but if it's higher they fail. When they use their luck they automatically subtract one point of their total luck points. They can use it after they roll but before you know the result. To make things more interesting and less abused I can make it so they don't know their karma/luck stat and I track it for all of them. I was also thinking about using karma or luck for things like stumbling upon hidden places or magic items, gold or opposite of that, them getting lost, or robbed or pick pocketed. 

Thoughts? 

Initial thought: Luck and Bountiful Luck, are available in the game.  What do you think of them?  I always evaluate what's already in place in the system before introducing something new.  I'll say on the luck front your system grants a lot more as far as a how luck's used in available game resources.  "Karma" I don't know if I'd do mechanically, as you're just putting a third force on top of DM Design and Player adjacency over the already randomized system of dice rolls.  I'd be more likely to treat it as sort of behind the scenes "boons" where if characters do the right things, doors are opened for them, sometimes quite literally.  

Quote from MidnightPlat >>

Initial thought: Luck and Bountiful Luck, are available in the game.  What do you think of them?

are you talking about the feats? I didn't want something they use for combat, and I for sure didnt want to give everyone a free feat. this is something for them, by them, based on their actions. In my mind it would help direct them towards good (i hope) so they dont become murderhobos or something. 

I suspect this is not a good idea.

If the goal of this system is to alter player behavior, then you can't secretly track their karma. You also need to be upfront and tell them every time they gain or lose a point otherwise they won't know what behavoir you are rewarding and what behavior you are penalizing. A player might assume they have done lots of good things and feel like their score should be a 15 but it's actually only a 12. Now they do a roll and a 14 comes up. They feel like they have been virtuous enough that they should have succeeded by they failed. Either they just decided the system is a dumb random lottery and it stops influencing their behavior or they ask you to explain to them why these five good things they did weren't good enough to count, or what bad things they did that hurt their score.

If you are transparent about what are good and bad deeds and what caused players to gain and loose points, that's better, but still risky. It does mean you can't have any morally ambiguous story lines in your adventures, because what happens when a player believes they were doing the right thing but you think differently? Unless you feel confident that youDo you get into an argument about morality with your players at the table? You might be surprised about what your player think is and isn't moral, especially in the world of D&D, where let's face it, most problems are solved by violence.

What if two of your players disagree on what the right course of action is? What if one player thinks it's okay to torture a cultist to find out the location of the ritual that will unleash an evil god upon the world. Maybe neither of you think that's bad, the end justifies the means, but what if another player thinks the good thing to do is take the moral high ground and not torture anybody?

In a normal game of D&D this can be an interesting source of conflict between characters, but now it's about who gets the point from the DM, so not only is a disagreement, but it's not even really a moral question anymore, it's just a gamified way of getting a bonus for your character.

There are games with mechanics like this. Some of them give you a permanent pool of Luck that once used is gone... say you start with 10 luck. You decide when you use them. 1 luck is deducted. When you get to 0, no more luck for the rest of the character's life. Some games let you get the luck back.

There are also temporary luck type points, such as Bennies in Savage Worlds.

I think however, that these mechanics would not work well in D&D. You might want to look into these other systems though... I think DCC has Luck, and as I said Savage Worlds has bennies. Read up on them... maybe you'd actually like to play one of those more than D&D.

You could implement burning exp for luck.

100 exp for +1 or -1 to a single d20 roll, BEFORE the roll.

1000 exp maximum on any one roll.

1000 exp maximum per long rest.

Yes, you can lose levels.

Putting myself in a player's shoes, this does not sound very fun. This sounds like pavlovian training, being forced into a specific pattern of behavior, potentially penalized for making the choices I want to make.

This is taken from Six Shooter on DMsGuild, you should check it out, it's really cool.

Luck is a 7th Ability Score, rolled with a single d20 at character creation. In certain situations that require luck, rather than skill, You roll a luck check, which is a flat d20. If you roll a 1-3, you fail, and your luck score decreases by 1. If you roll 4 to your luck score, you succeed. If you roll your luck score, it's a crit success. If you roll over your luck score, you fail(but not as badly as you would with a 1-3), and your luck score increases by 1.

I would not do it as a perpetual thing but I once ran a few sessions where the players were in a luck altering field.  Each day they rolled to see if they had good luck or bad luck (even or odd) then a d10 to see to what degree).  It was pretty hilarious seeing them struggle with a -8 to all attack, saving and ability scores for a combat or two.  But even more impressive seeing a +3 luck shift coupled with a bless spell to make taking down a dragon exceptionally easy. 

Fun for a while but not something I would like to track or implement for a long duration.

So looking at the proposal more closely it just seems like "you can roll, or you can play my luck mini game" it just seems tacked on as opposed to the systems that make use of luck and support the existing system.  What is "maximum success" anyway out side of combat crits?

As for karma, I think the Pavlovian comment hits that on the head.  Character builds won't always be in line with your standards of karmic conduct, so basically you're creating a mechanical incentive to comport to your expected behaviors in the game.  The game has Inspiration, stick with that or build off it.

i like, but i think you stole the idea from the completionist chronicles bro

So sounds pretty unanimous that its a bad idea, thanks everyone for your feedback I think I'll scrap the whole thing and just hope for the best, I dont want to micromanage player actions or try to force steer them .

Lastly in my first sentence I specifically said that I took ideas from other online sources, I never claimed the idea, albeit a bad one, was 100% mine... bro

Have you considered using a modified form of "inspiration" to stand-in for luck? That mechanic is already baked into the rules and there are several options for how to do it. For instance, you could use it like a "bennie" from Savage Worlds and let everyone start each session with inspiration. Or you could award say 20 inspiration "points" at the start of the campaign and let them spend them until they're gone... or something like that.