Even official Dungeons & Dragons material may lack balance and should be reviewed by Dungeon Masters to ensure the campaign is not broken.
While it is true that certain elements in official Dungeons & Dragons books are not properly balanced, it is ultimately up to Dungeon Masters to decide which elements to ban in their campaigns. Many DMs are already cautious of unofficial homebrew supplements and third-party mechanics, as they can be unbalanced, but some official materials also lack parity and should be evaluated on a case-by-case basis.
It is easy to conclude that because something is published by Wizards of the Coast and produced by professional game designers it should be balanced, but experience suggests otherwise. There is no evidence to suggest that Wizards of the Coast has ever produced an entirely balanced edition of Dungeons & Dragons, and a singular vision is not a realistic expectation for a game with multiple authors. Therefore, it is up to DMs to ensure balance and ensure that character options and abilities are balanced across the different editions of Dungeons & Dragons.
Though it may appear as a third-party campaign world, the Explorer's Guide to Wildemount officially made Critical Role an official Dungeons & Dragons setting. This is not to be mistaken for a balanced portrayal against core 5e rules, as it features numerous overpowered elements, particularly the Chronurgy wizard subclass. Notably, the Chronurgy wizard subclass is considered one of the worst offenders in the class, with its rerolling capabilities and Temporal Awareness ability providing significant advantages over other spellcasters.
The initial class features are quite powerful, with the probability-altering Chronal Shift ability allowing rerolls, and Temporal Awareness adding to Initiative rolls. However, Arcane Abeyance is a highly problematic ability that allows the caster to pre-cast a spell into a bead that can be activated by another creature, significantly reducing the caster's casting flexibility.
Other character options from the Explorer's Guide to Wildemount, like the Echo Knight fighter subclass, are arguably unbalanced and may require careful review by Dungeon Masters.
This ability circumvents the Concentration mechanic, as a Concentration spell cast by another character or a familiar would be resisted. Furthermore, it can be bypassed by a Ring of Spell Storing, but this item requires Attunement for optimal balance. Convergent Future further disrupts game balance by allowing the caster to force a success or failure on an attack, ability check, or saving throw without any limitations. Automatic success is reserved for boss monsters with Legendary Resistance, while the ability to force a failed save is considered abuse and should not be utilized.
Magic item balance in 5e D&D was messy due to the older Dungeon Master's Guide, but the newer magical implements and spellbooks in Tasha's Cauldron of Everything have further compounded the issue. The Wand of the Warmage requires Attunement, and its rarity ranges from Uncommon to Very Rare for its +1 to +3 versions, granting an enhancement bonus to the accuracy of spells that use attack rolls. The Arcane Grimoire and its counterparts from Tasha's Cauldron of Everything also share this rarity and Attunement requirement, but they also add an enhancement bonus to the DC of spells that rely on saving throws. The Dragonhide Belt provides a similar benefit for monks, but it is somewhat more balanced due to the absence of an attack roll bonus.
The twofold problems of these superior implements are evident upon examination. Firstly, they render the Wand of the Warmage obsolete by rendering it unusable in games with purchasable or selectable magic items. Second, they undermine the Bounded Accuracy concept that formed the core of 5e Dungeons & Dragons' design. Bounded Accuracy ensured that opposing figures' to-hit chances and Armor Class, or saving throws and spell DCs, remained tightly controlled within a specific range, making the d20 roll always relevant. Since the 5e Monster Manual was designed before these items, a caster with spells up to 15 percent harder to resist shatters both Bounded Accuracy and encounter balance.
Few players view the warlock as DnD's best spellcasting class due to its limited access to high-level spells, which hinders its effectiveness. However, online optimizers have discovered a peculiar benefit to the warlock class known as the "Coffeelock" build. This bizarre concept combines levels in warlock and sorcerer and exploits the Short Rest and Long Rest mechanics to generate an infinite supply of low- to mid-level spell slots. This allows players to bypass the typical spell slot limitations imposed by the class and significantly enhance their spellcasting capabilities.The gimmick of the Broom Of Flying lies in its relentless pursuit of Short Rests, leaving Long Rests far behind. Each cycle of Short Rests grants the wearer a potent spell slot, which can be replenished by warlock magic. These slots can be accumulated indefinitely as long as the character adheres to the restrictions of Xanathar's Guide to Everything. However, the DM is empowered to impose specific limitations that prevent the character from accumulating an excessive number of spell slots.
The Broom of Flying renders items like Wings of Flying and Winged Boots completely redundant. While both require Attunement for magical flight, the Broom's absence of a specific Attunement requirement renders it utterly useless in comparison. It can be sent for autonomous delivery, negating its primary purpose for granting flight.By far, the simplest solution is for DMs to eliminate this item from the game, which would leave players to rely on the more balanced flight items. If a DM is comfortable with the use of the broom for travel, they could simply house rule that it is not usable in combat, which is certainly a reasonable approach, given the difficulties of swinging a sword or dodging an arrow while awkwardly astride a flying broom. With a 50-foot fly speed, no time limitations, and no Attunement requirement, there is no reason the whole party would not be spending the entire adventure on magical brooms, leaving it up to the DM to impose a much-needed ban.
It is commonly believed that high-level Dungeons & Dragons is inherently imbalanced due to the power of high-level spells, and Baldur’s Gate 3’s level 12 cap allowed Larian Studios to avoid implementing spells of levels seven through nine. In truth, given the tighter limits on high-level spell access in 5e D&D, this is less of an issue than some might expect. There are a few exceptions, but a major one comes from misuse of the simulacrum spell. The Coffee warlock can generate infinite spell slots if left unchecked, but simulacrum can generate infinite spellcasters. While simulacrum is a powerful spell, its utility is limited by the fact that it only allows a wizard to create a single additional spellcaster, rather than an army of clones. Additionally, a level 20 Wizard has only two level seven spell slots, meaning that with enough time and resources, they cannot create an army of clones that can each cast a level nine spell in battle.If a wizard copies itself, the simulacrum gains the wizard's spell slots but cannot regain its lost slots. The copy can cast the spell again due to the spell slots it received from the original wizard. However, an army of copies will not benefit from this ability and will be lacking their full spell slots. The DM can decide to implement a specific house rule that prohibits simulacra from casting the spell simulacrum, or they can decide to make it entirely prohibited, rendering an army of wizards ineffective.