[UPDATE 6:04 12/08/21: This article has been updated to better reflect the 5e rules for D&D.]
Dungeons & Dragons is a game with nearly unlimited possibilities for its players, designed by extensive rules to keep gameplay fair and fun for everyone. With each new handbook edition the game releases, it adds changes and updates to the game to make it even more so. However, even in 5e, there remain ways for players to exploit gameplay by working within the game rules to break a campaign.
Exploits are distinct from Dungeons & Dragons overpowered classes in that they are about actions players take in a game rather than a character build. In the context of the game, exploits tend to refer to actions that work within the established rules to overpower or break gameplay. While using a Dungeons & Dragons exploit isn't explicitly cheating, it can significantly debuff challenges, which players and DMs alike may frown upon.
Dungeons & Dragons 5e removed or nerfed a number of exploits from prior editions, such as the Candle of Invocation, Warp Arrow, Wizard Bomb, and Cleave. DMs also have the power to limit the use of some of the remaining exploits to prevent their campaigns from being completely broken. However, there are still a number of ways for players to exploit Dungeons & Dragons gameplay, whether through class abilities, spells, or common objects.
Dungeons & Dragons: Class Exploits
Cantrips are spells that can be cast at any point during a D&D session unlimited times, and there's one the Cleric and Druid class share that significantly exploits gameplay. Dungeons & Dragons' Guidance cantrip can be cast by the player touching another party member, and the cantrip's recipient can add one d4 roll to any ability check, and the effect lasts one in-game minute until it's used. Cantrips can also be cast out of combat, so Clerics and Druids can help party exploit checks made while picking locks or persuading a local merchant.
Druids have another way to exploit gameplay through the Dungeons & Dragons Wild Shape ability. Though this ability isn't learned until level 2, Wild Shape allows Druids to transform into animals or creatures during combat or regular gameplay. The fifth edition of D&D attempts to regulate this ability by limiting the challenge rating (CR) of beasts players can transform into, and certain types are excluded until higher levels. For example, a Druid can't become a swimming creature until level 4, and level 8 is when flying creatures and beasts with a CR of 1 or higher are unlocked. However, turning into a small, harmless creature, such as an insect, can be very useful for recon. Additionally, during combat, damage taken while in Wild Shape does not affect players when they revert back to Druids, essentially giving them extra hit points.
Monks are one of the most OP classes in Dungeons & Dragons, allowing players to easily exploit combat. From level one, Monks can use an unarmed strike as a bonus action after attacking with a weapon or unarmed strike. At level 2, Monks learn Flurry of Blows, which after their attack action enables them to strike an enemy with an unarmed blow twice, at the cost of one ki point. Once Monks reach level 5, they can take two attack actions. Coupled with Flurry of Blows and their base abilities, Monks level 5 and higher have the opportunity to land four consecutive blows against an enemy.
Dungeons & Dragons: Spell Exploits
Simulacrum is a level 7 Dungeons & Dragons spell that only the Wizard class can learn. If players choose to add it to their repertoire, they can cause chaos in combat and completely overpower their enemies. On casting Simulacrum, Wizards can create a duplicate of any creature, sentient or beast, with the same abilities as the original. This is an exploit because (depending on the DM) it means a Wizard could duplicate themselves, and its copy would be able to cast Simulacrum as well, theoretically creating a small army of Wizards. This has the ability to completely overwhelm a player's surroundings, whether in combat or out and about in the town. What's more, this effect has no time limit to its duration, ending only when the Wizard who cast Simulacrum desires. Its only limitation seems to be that the spell takes 12 in-game hours to prepare, but any Wizard with foresight should be able to use periods of downtime to do so.
Fifth-level Bards, Sorcerers, and Wizards have the option to learn the Animate Objects spell, which brings up to 10 otherwise inanimate objects to life. For up to one in-game minute, the caster can command the animated objects to do whatever they want. Each level after 5 adds two additional objects the player can animate. The rules of Dungeons & Dragons attempt to limit this exploit by having larger objects count for multiple spots within the ten, but it remains a powerful exploit to cause Beauty and the Beast-style chaos during combat and roleplay alike.
Dungeons & Dragons: Action & Object Exploits
One rare but valuable object that can allow players to break a D&D campaign is the Instant Fortress. When not in use, it's an easy-to-carry, one-inch metal cube, but if a player places it on the ground and speaks its command word, it transforms into a 30-foot high tower. When the fortress first appears, every enemy must make a saving throw; if they fail, they take 10d10 bludgeoning damage, and if they succeed they only take half that amount. Additionally, players can hide inside the Fortress, which has 100 hit points per wall, roof, and door.
Short rests may seem like innocuous, less powerful versions of the long rest, but they can be deceptively exploited. According to the Dungeons & Dragons 5e handbook, short rests only need to be one hour long and allows players a chance to regain hit points and used spell slots. Coupled with items such as the Instant Fortress, players can theoretically use short rests to completely ready themselves for battle - even in the midst of ongoing combat against lesser enemies.
Dust of Sneezing and Choking is a fun, albeit dangerous, exploit. It's not a rare item, so in theory players should be able to buy or loot the Dust with relative ease. When tossed into the air during Dungeons & Dragons combat, everything in a 30-foot radius, including the player and any allies, must make a Constitution save of 15. On failing, affected entities lose the ability to breathe until they out. With one simple action, Dust of Sneezing and Choking can allow a Dungeons & Dragons player to render an entire group completely helpless.
