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DnD’s new DM Guide destroys a classic broken character build

Dungeons and Dragons includes a ruling against the classic ‘Bag of Rats’ exploit in its 2024 Dungeon Master’s Guide – sorry, power-gamers.

Wizards of the Coast art of a rat in a DnD Bag of Tricks

Wizards of the Coast’s new DnD Dungeon Master’s Guide is filled with advice for new DMs, and one tip it provides seems to nullify the ever popular ‘Bag of Rats‘ exploit. Chapter One includes a section called ‘Ensuring Fun For All’, with the following guidance: “Some rules apply only during combat or while a character is acting in Initiative order. Don’t let players attack each other or helpless creatures to activate those rules”.

This seems to conflict with the ‘Bag of Rats’ trick, an exploit or DnD character build that has existed in Dungeons and Dragons since at least third edition. The concept is pretty simple. Step one: Carry around a bag of hostile but weak creatures, such as rats. Step two: Kill some of these creatures whenever you need to activate an ability that triggers when you kill a hostile.

Step three varies, depending on what you’re trying to achieve. Some DnD classes can use the Bag of Rats to farm additional damage, temporary hit points, or extra attacks. Targeting a rat with a DnD spell might bypass some key bit of setup.

In 3.5e, Fighters commonly combined a Bag of Rats with Great Cleave and Whirlwind to give them a huge number of free attacks against a more powerful DnD monster. The spell Consumptive Field would also grant 1d8 of temporary HP for each creature reduced to zero hit points within 30 feet of you – perfect for farming with a Bag of Rats.

DnD 2024 Dungeon Masters Guide destroys broken Bag of Rats build - Wizards of the Coast image showing the 2024 DMG cover art overlaid on a piece of art showing an adventuring party

Some fifth edition rules still interact with this concept, too. A Phantom Rogue could kill those rats to generate a new Soul Trinket for cheap, or a Ranger could technically kill a horde of rats outside of combat to ensure their Hunter’s Mark remains active between fights. If a Necromancy Wizard kills a creature with a level-one-or-higher spell, they regain hit points equal to twice the spell’s level – cue the Bag of Rats.

The Bag of Rats has become synonymous with a style of play that twists and exploits the core Dungeons and Dragons rules. This is the kind of optimization that relies on technicalities and loopholes, and many Dungeon Masters hold no truck with it. That explains why Wizards of the Coast themselves have dissuaded such play in the new Dungeon Master’s Guide.

In fact, this isn’t even the first time such advice has appeared in a first-party D&D product. The fourth edition Dungeon Master’s Guide included a ruling about legitimate targets for attacks, saying: “For instance, characters can gain no benefit from carrying a sack of rats in the hope of healing their allies by hitting the rats.”

For more on the new book, check out our full 2024 Dungeon Master’s Guide review. We’ve also revealed that the DMG has a bunch of tasty hints about the 2025 Monster Manual – and that the book has some unexpected celebrity DM consultants.

We can also explain all the new rules for DnD Bastions found inside – as well as all the DnD races and how they’ve changed in the 2024 ruleset.