What mechanical effect should being especially lucky or unlucky have in RPGs?

What mechanical effect should being especially lucky or unlucky have in RPGs?

I'm more in favor of letting your own luck decide. You are already rolling dice, let fate decide.

From Pathfinder, and more specifically its SRD:

Bonus

Bonuses are numerical values that are added to checks and statistical scores. Most bonuses have a type, and as a general rule, bonuses of the same type are not cumulative (do not “stack”)—only the greater bonus granted applies.

Bonus Type: Luck
A luck bonus represents good (or bad) fortune. Multiple luck bonuses on the same character or object do not stack. Only the highest luck bonus applies.
Can Affect: AC, attacks, checks, damage, saves

So basically the simplest way of rendering luck mechanically is a simple bonus, or minus, to a roll.

Depends on the system/setting but you could make them roll a smaller dice size.

Keep away from static modifiers would be my advice. They're boring, hard to carry, and your player will look for a way around them.

Monster of the Week has an interesting Luck system.
It's an Apocalypse World-based game, so when you fail a roll, the GM makes a move off of his list. These are usually divided up into soft and hard moves. Soft ones have no irrevocable consequences, and are usually the setup: "The room begins to shake violently and the ceiling cracks." Hard moves have immediate consequences, and are usually the follow-through: "The roof collapses in on your character."
Characters have a set amount of luck, depending on their type, usually about 6 or 7 points. When you fail a roll, you can burn one of these points to succeed instead. Great, right? A point burned is gone forever, however. A few classes can get one or two more at great cost, but normally you don't get them back, and a character marches down the track from "Okay" at full luck, to zero luck, at which point he is "Doomed."
Doomed is a special condition. When a character is doomed, the GM stops making soft moves. E.G., no longer do you see the trapdoor in the old murderhouse before falling through it. Everything changes and the world starts to feel like Final Destination, where bad stuff just keeps happening to you until you die, or until you find some way to fix your luck, either by burning one of your class upgrades if you're the right class to be able to do that, or else by tracking down a real good luck charm somewhere, and clinging on that thing tight.
It's a great, atmospheric mechanic, although I'm not sure how you'd port it to a non-Apocalypse based system, since it kind of hinges on the move structure.

Rerolls seem appropriate.

Are there any non-obvious things in this photo? I see the umbrella, ladder, salt, mirror, cat, friday the 13th

None, because luck isn't real.

>but wizards throwing fireballs is totally real

in the context of the game magic is real
that doesn't meant that everything else that isn't real suddenly has to be real

Please inform us of what luckless game with magic you are playing.

You already lost WoD, GURPS and 3.5/pf off the top of my head so let us know.

That's a total non sequitur, user. You can't say "there shouldn't be mechanics for luck because luck isn't real" without implying the same thing about magic. Magic, like luck, is a thing that does not exist, yet people widely believed in it, and had elaborate notions about how it worked.
Hell, in a lot of primitive societies, luck and magic are the same damn thing.

Luck cucks trying hard as fuck to defend shitty metagame mechanics

Troll trying to use methods from a decade ago.

If you're trolling then you're doing a great job because I am simultaneously amused and annoyed.

There's no reason to discount luck in a system with magic or anything supernatural. If you can manipulate magic to summon balls of fire out of thin air then why not use magic to give you a small, virtually unmeasurable advantage in the next thing you do?

Because magic is cool and luck is retarded? Stop trying to inject your wishful thinking from real life into the game. I'm sure you're one of those idiots who demands that every fantasy game now include trannies, right? You fuckin' people

Since we're busting out the old memes, I guess I'll do this one: OBVIOUS TROLL IS OBVIOUS.

>help help someone disagrees with me they are trolling mom help janitors delete this post

I'm a fan of something super-meta, like spending bennies in Savage Worlds. Character gets luck points, spends them on bonuses or rerolls, up to a maximum number of points per game session.

Mechanically gaining this ability should leave your character somewhat below-par on their abilities (by not spending the feat or build points or XP or whatever else on an "always-on" ability instead), but allow them to be above-par when spending their points, creating a strategic choice about using them when they will count the most and reflecting the concept of a plucky adventurer who's a bit of a burden most of the time but always pulls through when it matters.

>luck is retarded
Great opinion m80. A character who kind of sucks but keeps getting by on luck is a terrible idea that nobody could want to play.

What is this, a reddit post about what it's like to have brain damage?

Go cry to your hug box, you fuck.

At the beginning of each session, roll a die. Every [result] roll after that is made with twice the dice - lucky characters get the highest results, unlucky get the lowest.

Did you use one of your bennies to help you with that post?

On one hand, this seems like an incredibly neat mechanic.

On the other hand, it seems like a PC with any sense would just never spend their last luck, since being "Doomed" seems way worse than failing a single roll.

It's all about strategizing, and the temptation of the moment.
Failing a roll could put you in a really bad spot, even outright kill you. Imagine the GM has just made that "the ceiling cracks" move and you've tried to climb over the stacks of newspapers the crazy old man left in the basement to escape. If you failed the roll and got stuck, you're looking at the possibility of the murder house collapsing on top of you, burying you alive. Sure, maybe your friends will be able to get you out, or maybe you should burn that last luck point to escape the collapse unscathed and hope you can survive to the end of the episode, then open on a new mission to follow the legend of Boxcar Joe's lucky rabbit's foot, that was blessed by a priestess of Voudoun and is supposed to really work.

I guarantee though, that when you're down to that last point, you start sweating, and thinking about all the earlier points you used, and how maybe you should've saved a few of those. But at the end of the day, the monster hunting life is bad news, and it rarely ends in a happy retirement.

Shoes on the table

Khaki shorts and porch decoration lights.

Porch lights are unlucky? Didn't see that in Brewer's Phrase and Fable.
Can you give more detail?

They're Christmas lights, it's unlucky to put them up before Thanksgiving. Not that it stops many people these days.

Aaaaaaaaaaaaaaah.

Any roll of a max or min number has an additional effect (doesn't have to be major) that the DM considers highly unlikely. Keep in mind this essentially adds crits to things that normally wouldn't have them.

>Lockpick door
>Roll 20
>There was a guard on the other side of the door lying in wait
>But you opened the door so abruptly that it sent a book that was on the ground sailing right into his foot
>No surprise round

I'd prefer just giving someone advantage/disadvantage than having them juggle six different bonus/penalty sources, in addition to situational modifiers.