Hey folks, I was hoping to get some help judging the power level of a homebrew item for a druid. This is specifically geared towards a moon druid.

Mark of The Pride
Must be attuned by a Druid. While attuned to this item the druid only regains wild shape on a long rest and gains 3 of them.

Guile of the Wild
When you attune to this item, you learn the Tactical Assessment, and Goading Attack maneuvers and gain a superiority die which is a d8 ( d10 at level 10, and d12 at level 18). You regain this die on a short rest. While in wild shape you may use a bonus action to expend a spell slot and regain 1 superiority die per spell level.  You may regain a number of superiority dice in this way equal to your level per long rest.

Boon of the Fittest
Once per day, you may approach a beast of a CR which you can wild shape.  If you are able to touch the beast and focus on it you may form a mystical connection with its species.  The creature must succeed a wisdom saving throw or be paralyzed. The beast may repeat the saving throw each round to end the effect.  A friendly beast may automatically fail this DC. If the beast fails this saving throw, and you have never successfully targeted a beast of this type with this ability before, you may learn a new combat maneuver you feel is associated with the creature type.  You may learn a maximum number of maneuvers in this way equal to your Wisdom modifier.

IMO, it is both Overpowered and Terrible.

First, the Terrible:

For one thing, 5e doesn’t use “may” it uses “can.” (May means “allowed to,” can means “are capable of.”) For another thing, a creature cannot “fail [a] DC.” They don’t “make a DC,” they make a Saving Throw, the DC is a metric for determining how hard the Saving Throw is. And they wouldn’t “automatically fail,” they “[could] choose to fail” the save. And magic items are designed by nature (with very few highly notable exceptions) to be static and not evolve with their wielders’ level.

But most importantly, nerfing Wild Shape to a long rest feature is brutal, even with the extra use. (That’s a Druid’s main class feature after all.)

Now, the Overpowered:

This is technically more powerful than the Martial Adept feat, heck, it more powerful than the actual Battle Masters’ Combat Superiority feature. (Their main feature.) At max they get to learn 9 Maneuvers, 3 @ 3rd, and then 2 each at 7th, 10th, and 15th. Then, they only get 4 dice, and another at each 7th and 15th levels for a total of 6.

Your item gives the Druid 2 Maneuvers immediately and then they can learn an additional 5 (6 if they read the right book) for a total of 7-8 Maneuvers which is almost as many as the Battle Master gets, and they could potentially have up to 21 Superiority Dice per long rest. (That would require a Battle Master to take 3 short tests per day to get that many.

My suggested alterations:

(Insert a name more reminiscent of an “item” here)

Wondrous Item, varies (requires attunement by a druid)

 

When you attune your this magic item you gain the following benefits:

• You learn either the Goading Attack or Menacing Attack maneuver, and a number of additional maneuvers of your choice from either those available to the Battle Master archetype in the fighter class, or as optional fighter class features. The number of maneuvers is determined by this item’s rarity. If a maneuver you use requires your target to make a saving throw to resist the maneuver's effects, the saving throw DC equals your druid spell save DC. 
• You gain one superiority die, which is a d8 (this die is added to any superiority dice you have from another source). This die is used to fuel your maneuvers. A superiority die is expended when you use it, and you can only use this superiority die while you are in Wild Shape. You regain your expended superiority die when you finish a long rest. In addition, while you are in your natural form you can replace this superiority die as a bonus action by expending a spell slot of 1st level or higher.

Rare: 1 additional maneuver, Very Rare: 2 additional maneuvers

Thanks for pointing out how terribly my rules were written, but somehow you seem to have dodged the intended question. I'm aware that reducing to a long rest is brutal.  The question is about whether the brutality of that is in-line with the OPness of the replenishable dice.  You are correct that at higher levels it becomes too many maneuvers.  I was thinking my spell slot burn made up for it because im essentially trading 1d8 of my own hp for 1d8 damage plus utility, but now I realize you are correct.  Regarding "And magic items are designed by nature (with very few highly notable exceptions) to be static and not evolve with their wielders’ level." I'm aware of this, however, in our campaign the DM has awarded items that grow with us.  We are allowed to play dnd how we want yes?