How powerful would this ability be?

[Ziegander]

"You have advantage on melee weapon attack rolls against any creature with a Charisma score lower than yours."

[heavyfuel]

Pretty freaking powerful. This would make Paladins and Warlocks much better classes. Sorcerers and Bards as well, and the deities know these last two don't need any help.

[Shadow]

Pretty freaking powerful. This would make Paladins and Warlocks much better classes. Sorcerers and Bards as well, and the deities know these last two don't need any help.

Rogues even more so.
Cha becomes the primary stat, not Dex.
Everyone likes to approximate advantage as approximately equal to +5 to the roll, so advantage is approximately equal to +10 to your attack stat. That means Cha is more powerful BY FAR than Dex on a rogue. Who cares if you do a point or three less damage if you are guaranteed sneak attack every attack, no matter what?

This ability would be ridiculously OP.

[Ziegander]

I failed to consider Rogues. Rogues do make it much more powerful than intended, though I don't mind Sorcerers and Valor Bards getting mileage out of the ability and I did assume it would be a GREAT BOON to Paladins and Warlocks...

Hrm... I think I can restrict it from a flavor standpoint, even though it still feels a bit like a kludge.

Okay, what about this one? "While flying, you have advantage on all weapon attack rolls made against creatures that are not flying, and all weapon attack rolls made by creatures that are not flying have disadvantage against you." Absurdly powerful?

[heavyfuel]

Flight thing had a precedent in 3.5, where you got bonuses from higher ground, but it was a measly +1 for melee only. Giving what's effectively +4 to your attack and to AC for both ranged and melee attacks simply because you're flying is bonkers too. Flight is already powerful enough as it is since it basically makes you untargetable by anyone that likes to use a melee weapon.

If I may ask, why (from both a fluff and from a crunch perspective) are you asking these things?

[Ziegander]

If I may ask, why (from both a fluff and from a crunch perspective) are you asking these things?

Oh, I'm worldbuilding a little, trying to design new abilities for new creatures.

[Shadow]

Anything which offers advantage with no extra work on your part, or because you're doing something that you probably want to be doing anyway, is absurdly powerful.
Advantage shouldn't just be available so easily. You need to create a situation where you actually have some significant advantage above and beyond what would normally be.
Pretty much any ability that you create which just offers advantage for zero expenditure of resources or set-up is going to be OP. And no, spending a spell slot on some other ability/spell doesn't count as resource expenditure, because those resources were expended for a different purpose.

[Slipperychicken]

"You have advantage on melee weapon attack rolls against any creature with a Charisma score lower than yours."

"Once per short or long rest, you may spend a bonus action to quickly strike a series of flamboyant poses while shouting (usually the name of a technique, a brief self-introduction, a challenge, or a quick speech admonishing your foe). Select one creature which has line of sight to you. You gain advantage on melee weapon attack rolls against it for the next minute. This ability does not work against opponents whose charisma score equals or exceeds your own."

[Shadow]

"Once per short or long rest, you may spend a bonus action to quickly strike a series of flamboyant poses while shouting (usually the name of a technique, a brief self-introduction, a challenge, or a quick speech admonishing your foe). Select one creature which has line of sight to you. You gain advantage on melee weapon attack rolls against it for the next minute. This ability does not work against opponents whose charisma score equals or exceeds your own."

But you have to make this an alternate ability for Assassin Rogue.

http://media.giphy.com/media/L3AKVMrUyv30c/giphy.gif

Maybe splash Monk.

http://cache.reelz.com/assets/content/repFrame/44582/RMMSrelax121209.jpg

Drow is a definite possibility.

http://cdn2.thegloss.com/wp-content/uploads/2010/09/zoolander.jpg

[heavyfuel]

"Once per short or long rest, you may spend a bonus action to quickly strike a series of flamboyant poses while shouting (usually the name of a technique, a brief self-introduction, a challenge, or a quick speech admonishing your foe). Select one creature which has line of sight to you. You gain advantage on melee weapon attack rolls against it for the next minute. This ability does not work against opponents whose charisma score equals or exceeds your own."

As a feat or class ability (lv 3 minimum) this might be OK. As something anyone can simply do with their bonus action, it's still really strong


But you have to make this an alternate ability for Assassin Rogue.

Maybe splash Monk.

Drow is a definite possibility.

OH MY PELOR! This is so good hahahaha