Can I stop this homebrewed Lucky Coin ability from being exploited?

Question

My group has a cleric of Tymora (goddess of good fortune) and I am considering giving them a custom magic item that ties in with the idea of luck. The item is a coin with Tymora on one side, and Beshaba (misfortune) on the other.

Lucky Coin

As a Bonus Action, flip a coin. If heads, you must apply advantage to your next attack roll or spell attack roll. If tails, you must apply disadvantage to your next attack roll or spell attack roll. The lucky coin cannot be used again until a short rest has been completed.

The item is mainly intended to allow the cleric a little more role-play in combat. My question is how can I alter this magic item to prevent it from being exploited? One possible exploit I've thought of is the PC waiting until they already have disadvantage against them, but there may be more that I haven't considered.

Answer 1

Abuses of this will center on avoiding disadvantage on rolls that are important to the current situation. In particular, there's no time limit on this, so the player could just use it out of combat and either use up the disadvantaged roll attacking something irrelevant, or keep the advantage until combat next starts. As you've mentioned, there's also the possibility of using it only when the character already has disadvantage. I'm not sure that's really abusive; it seems to fit the purpose of the coin pretty well, fiction-wise, so it should just be taken into account. Likewise, changing behavior to use more powerful spells, class features, consumables, or the like after gaining advantage, and vice versa, is obviously the entire point of the coin flip in the first place, just as it would be for any other omen.

However, putting a one-minute time limit on the effect would prevent (most) out-of-combat uses without damaging the basic luck concept.

Answer 2

It is fine as it is

Smart players do not even have disadvantage once per short rest.
Power players have much more potent things to do with their bonus actions.

Just make the player announce first what the ability is used for, so he can not use a cantrip if he got disadvantage and a 9th level spell if he got advantage.

Answer 3

As it stands, the item is not particularly ridiculous. It's significantly weaker than a typical magic item rated at Uncommon. So from that perspective, it's not game-breaking.

However, the item is really hampered by this wording: you must apply advantage to your next attack roll or spell attack roll.

There are a few problems here:

• You specify attack roll or spell attack roll, that's unnecessary. the wording would simply be you get advantage on your next attack roll.
• There's no time limit on usage. This means that I can use my bonus action out of combat and the ability just sticks around forever. Heck, I can save it up over days. So, as written, the ideal way to use this is to flip it in the morning and just carry around your advantage until you need it.

None of this is "broken", but I think it violates the spirit of the item. Instead, I would write this as a trigger.

When you make an attack roll on your turn, you may choose to spend your Bonus Action to flip the coin. On a heads, the attack roll has advantage; on a tails, the attack roll has disadvantage.

You could probably downgrade this to a Reaction and it's probably still fair. The Reaction might even be more flavorful. For extra fun, make your player flip the coin and roll both dice at the same time :)

Answer 4

There is no exploit issue here.

The Magic Item is considerably less powerful than the Lucky feat, Halfling's Luck, or the Wizard's Portent ability.

Yes, it can grant advantage. It might even grant it at a very opportune time. That's the point of a magic item: to increase player effectiveness. What you're calling an "exploit" is basically just "using your magic item".

Even your exploit example is of a weak power level. If you use it when you have disadvantage, the best it can do is nullify it. It can't grant you advantage in this situation, since the one cancels the other. I'd give it to a Tymora cleric without hesitation, as the flavor is good, and the effect negligible.

Answer 5

It is in the very weak side.

1. There is no reason to use this coin if the player has the advantage, therefore, at most they would use it on a normal attack or, at best, they would save it when they are at disadvantage (since it cannot get worse).
   1.1. In the long run, statistically speaking, if they use it on a normal attack they would have 0 benefit from it (50% of the time is good, 50% is bad) without sneak attacks.
   1.2. The damage increase on a sneak attack attack would be negligible*.
2. Having advantage does not mean that the attack would succeed, just that it is more likely to succeed.
3. Because of 2, If the PC/NPC have other things to do with its bonus action, it would be better to use those, particular at will.
4. It is only once per short rest. It is too low to be useful in non disadvantageous situations, thus, waiting for one is not an exploit, it would be probably its best use.

*- If we consider a 50% of hitting a target and a 10d6 sneak attack, the damage once per short rest would be, statistically speaking, a 3.75d6 (~4d6 avg ~14, an off-hand bonus attack with a rapier at will will yield on avg 4.5 + 50% chance increase to apply sneak attacks). The damage increase would be too low for a Rogue, even if you math in the critical chance (~10% vs 5%).

Balance issue

Statistically speaking, the advantages of the coin are extremely low, thus making the coin usable at least 3 per short rest, or 5 per long rest would definitely increase its uses.

Discouraging uses on attacks with disadvantage

A way to discourage is to apply a double punishment (probably rewards too) on usages in determined situations. For example, adding a 1d10 damage (radiant, double on critical fail) on the user if it lands on Beshaba on an attack with disadvantage is a very good way to dissuade this "abuse". On the other hand, risking an advantage for an extra 1d10 damage (radiant) on the enemy would be kind a cool if you ask me. If you consider this, I would balance the usage at 3 per long rest.

Answer 6

This seems balanced as-is.

One thing you can do is say that the advantage or disadvantage is applied on the next turn, instead of the same turn as the coin-flip. That said, most players will not have disadvantage once per short rest, and when they do it's often for more than one turn.

Also, seeing as this item is related to luck, this coin could work only with your cleric, however I would then foresee problems from the other party members.

Answer 7

Honestly, I think the coin as it stands is pretty terrible. I'd change it to:

Lucky Coin

As a Bonus Action, flip a coin. If heads, negate disadvantage on your rolls until your next turn. The lucky coin cannot be used again until a short rest has been completed.

Even that isn't particularly good, but it's still good enough it might be helpful.

After a bit of thought I think, were I to give this to one of my players, I'd do:

Lucky Coin V3

As a Bonus Action, flip a coin and negate disadvantage on this roll. If heads, also gain advantage on your rolls until your next turn. The lucky coin cannot be used again until a short rest has been completed.

And another thought occurs to me (considering the back side is misfortune):

Lucky Coin V4

As a Bonus Action, flip a coin and gain advantage on this roll. If heads, also gain advantage on your rolls until your next turn. If tails, the next attack or ability check made against you gains disadvantage. The lucky coin cannot be used again until a short rest has been completed.

Answer 8

Since this is an ability of the cleric's god, why not make it similar to one of their class features. Allow the coin to be used only by the cleric, and usable (Wis mod) times per day. Player declares an action, and tosses the coin. On a success (heads) it grants advantage to that action. On failure (tails) it grants disadvantage.

I'm not a fan of it actually being a coin, though. How awkward is it to constantly toss a coin around when doing other things? (After all, that's how Two-Face dies in Batman Forever) What if you made it a magic coin that attached to the cleric's armor or gauntlet. When touched, it would spin, and come up heads or tails (in RP land this could happen while the attack was partway completed). Heck, even give it a little firework effect that bursts between the cleric and the target of either symbol.

Answer 9

To an everyday adventurer luck is the most important thing.

All the answers seem to be forgetting one thing: Rarity

What rarity do you want this magical item to be?

What level are the players?

How is the magical item distribution in your world?

Do they already have Rare or Legendary magical items or just Common and Uncommon ones?

These are all important questions that require answers to determine if a magical item is more powerful than it should be. Only sure way to tell if something is broken, power wise, is to compare it to something of equal rarity.

But i digress, the question was how to stop it from being exploited. My answer is to tweak it a little bit more, add in a little more power to the good side of the coin, but take the control of the bad side. At the cost of some player agency some might say.

Fair warning: With this version the resposibility to not exploit the effects of this magical item will be on the DM. If you don't have a trust based relationship with your players (i.e. "DM is out to kill us") your players may not like this item.

Lucky Coin

You can flip this coin as a bonus action, on one side of the coin there is fortune, and on the other: misfortune.

Fortune: When the coin lands on this side the Goddess of Good Fortune smiles upon you, you gain a luck point* until the end of your next short rest. -Luck point works the same way as Lucky feat-

Misfortune: When the coin lands on this side, you get the attention of the Lady Doom. Misfortune may visit you anytime until the end of your next short rest. -DM's call to whether explain this to players or not but basically a reverse luck point* for the DM to use against the player before the next short rest.-

*: On a second thought the luck point from Lucky can turn a disadvantage into 3 dice advantage so maybe too much. Can be changed to 'gain advantage'.

The balance is in your (DM) hands and your duty not to exploit it against your players.

Answer 10

I would make sure there is a penalty to getting tails when already disadvantaged. Some ideas are:

• Add another die to disadvantage

• Maybe the patron diety of luck curses them in some way. Be it a penalty to luck of sorts (maybe to their next saving throw or to their next attack/damage roll) or maybe even the user suffers damage from them.

All in all don't make it so severe that they fear using it but definitely make them second guess trying to counter bad luck and not suffer the consequences for failing.

Answer 11

It's broken because Cleric will often carry Advantage better than the Luck feat.

As written, the item could be hacked by performing an attack or spell attack to remove any carried Disadvantage. If that's desired - then that's fine - it is doing what is intended - but if it is meant to be neutral as you write then it will need remedies (below.)

Disadvantage can be removed almost anytime.

As written, the Cleric can get rid of disadvantage almost anytime. The item doesn't specify what prevents the cleric from performing any type of attack which induces a roll (i.e. taking a sling at birds or fence posts) thus removing any Disadvantage. Additionally, if your cleric ever gets a cantrip with a spell attack (i.e. by multi-classing or taking a cantrip Feat), then there's nothing in the item description to prevent them from casting the cantrip over-and-over to remove Disadvantage.

This means that as written, 50% of the time between short rests, the cleric will be carrying Advantage.

Depending upon how many short rests the party take - that item could be as good or better than the Luck feat.

If that is not what you intend, and you truly want it just to give role-playing opportunities as you mention and not increase power, then there are some remedies.

One solution to make it balanced: make the rolls simultaneous.

If you truly want it to be random and non-hackable, one solution is this: a PC decides to flip the coin, throws it in the air, takes a swing or casts a spell, then the coin lands in their palm (or on the ground) and they discover if they were lucky.

Alternatively, the PC flips the coin but the coin doesn't reveal its face until after the action.

Answer 12

Two Ideas

• Make the Usage a Long Rest
• Make the Usage time a whole action

Your trinket seems fairly well balanced honestly. It really depends on how many short rests your party takes.

Answer 13

This seems fine as it is as there is an even chance of fairly equal positive or negative effects. If anything it is a bit bland as the net effect over a number of uses should be neutral so it might even be considered a waste of an action.

I would actually consider spicing it up a bit so that there is a good chance of a reasonably good effect but some chance of a really bad effect.

From a role-playing perspective an item like this implies that the character is a gambler, so even odds of a small positive or negative effect seems a bit pointless and doesn't really add much to an event which is already random.

There is also an argument that for something which is supposed to be about luck just having a chance for a statistical buff isn't very distinctive or exciting. Much more interesting would be to have a table of exotic effects which you keep secret from the players, which could be a mixture of good, bad, and just plain odd, which might reflect real world good or bad luck. Say to give a bit more flavour you could flip it at the start of a day (depending on how you want to define a day) rather than just having it as a combat modifier and more of a good day/bad day sort of thing for example on a D20:

1. through careless packing you lose one randomly selected item from your inventory
2. you are filled with confidence: any action has a 50% chance of adding advantage
3. butterfingers: any action has a 50% chance of having disadvantage
4. spared by fate: the next attack which reduces you to 0 HP is ignored
5. total concentration: automatically pass one skill check
6. you find an abandoned chest containing (random loot)
7. you find an abandoned chest containing (random loot) … unfortunately it is cursed
8. food poisoning: reduce strength by x

etc etc...

To me this seems a bit more interesting for role-play as you get more of a sense of a run of good or bad luck and players will need to persist a bit to see what is on offer.