How To Run A Tarrasque Encounter In Dungeons & Dragons

The Tarrasque is a favourite high level encounter for Dungeons & Dragons, serving as a victory lap for level 20 parties that have beaten their campaigns or as a fun punching bag for testing experimental builds in a one-shot game. Since it awakens and attacks randomly you can conceivably run this encounter at any point, although doing so without preparation will come back to bite you.



Related: Dungeons & Dragons: How To Run Large-Scale Combat

With a challenge rating capable of matching Aspects of the deities Tiamat and Bahamut, this encounter can serve as a test of the player’s mastery of their characters and the DM’s understanding of the system.

Find A Way To Incorporate The Tarrasque Into The Story

The Aspect of Bahamut, a Tarrasque, Acererak and Tiamat, High-Level enemies in Dungeons & Dragons

On its own, a hard to destroy reptile doesn’t offer too much as an antagonist: The monster has four intelligence and 11 charisma, so it isn’t going to be giving grand monologs or developing hidden agendas by itself. Since it’s hostile to all other creatures it isn’t going to have allies, rivals, supply lines or strategic objectives that players can leverage either.

Having the Tarrasque be subjugated by a more personable antagonist can allow for more elaborate storytelling and provide alternative solutions the players can pursue. If your main villain is flaunting the Scroll of Tarrasque Summoning as a weapon of mass destruction, the players might be able to ‘defeat’ the Tarrasque by stealing or destroying the scroll.

The other way of incorporating the Tarrasque into a narrative is to make it analogous to a natural disaster. If it has been out of dormancy for some time or its awakening has been anticipated by divination magic, you can construct political encounters out of building defensive alliances and mustering armies to help defeat it.

A party below level 20 might take on supporting roles in fighting the Tarrasque, serving as diplomatic envoys or searching out magical relics that can help defeat it. It may be that rather than aspiring to defeat it, a Tarrasque centered campaign could focus on how to rebuild from its destruction, lure it away from population centers and predict where it will reappear.

Let Your Players Develop A Plan Ahead Of Time

Dungeons & Dragons art of various playable species
via Wizards of the Coast

Any battle capable of challenging a level 20 party should offer that party a chance to consider their options. Set aside some time to discuss how the players want to approach an encounter with the Tarrasque.


Methods Players Might Use

Preparation Required


Legend Lore, history skill checks, library research

As the GM you should decide what information will be provided for differing levels of success.

Buffing before the fight

Foresight, Death Ward, Freedom of Movement, potions of haste and strength.

Players will need to pay careful attention to which buffing abilities can be used without breaking concentration.

Transformation and polymorph forms

Shapechange spell and Druid’s Wildshape

Shapechange provides a massive number of options that can slow down the game severely if the player is not familiar with them.

Players will need to prepare for which forms they want to shape into and have the character sheets for those on hand.

Choose where to fight

Track the Tarrasque’s movement and determine where to interrupt it.

To save yourself from having to prepare maps for all possible scenarios you can have this planning occur in a session ahead of the actual combat.

Determine how different maps might influence the fight, giving situational bonuses.

Find a magical item that can help with the fight

While not present in the Fifth Edition Monster Manual, many tables carry forward the rule that the Tarrasque can only be permanently killed if a Wish spell is cast on the defeated Tarrasque. Securing a scroll or item able to achieve this may be part of the preparations your players choose to do.

Have side quests available that allow the players to gather tools and allies.

Set an in game time limit to force them to choose between the different options.

You will have foreknowledge of how the players plan to handle the encounter but should be careful to not abuse this knowledge. The Tarrasque is not an intelligent creature and if the players outsmart it, that should be a well-earned victory.

However, you can consider how it might react to scenarios the players put forward. For example, If the players plan to snare one of its legs in a trap to prevent it from escaping you might consider whether the Tarrasque is more likely to bite its way through the trap or continue fighting while bound.

Familiarise Yourself With The Tarrasque’s Abilities

giant dinosaur monster fights adventurer group
The Tarrasque by Filip Burburan 

The Tarrasque has a simpler toolkit than most encounters at CR30, but that’s largely because the other two are both deities. Each turn it uses its fear aura and then makes five attacks.

With the amount of text those attacks take up it can be easy to forget that the fear aura cannot affect a creature that has passed its save once, that the bite attack forces a grapple check and that it also takes three legendary actions per round.

Another important feature to remember is the unique Reflective Carapace it has. Advantage on all saving throws against magic and the ability to reflect spells using attack rolls make the Tarrasque incredibly resilient against spellcasters, but they require you to know how these features work and remember to roll for them whenever a spell is cast.

The attacks it deals are less complicated than the passive abilities, but you will still want to note the special effects on the bite and tail:

  • The bite grapples a creature failing a DC20 athletics or acrobatics check, and allows it to use its swallow attack which is the Tarrasque’s only source of elemental damage.
  • The tail attack knocks an enemy prone if they fail a DC20 strength save.

Using the tail attack first to knock an enemy prone will to give the Tarrasque disadvantage on follow-up attacks, unless it moves within five feet. Some GMs may decide this rule makes no sense and ignore it.

The legendary actions you will want to use in response to specific strategies the players bring out.

  • If they’re making evasive plays the tarrasque can use one to move half its speed. This can also be used to maneuver around any characters trying to block its path.
  • The combo of making a bite attack on its own turn and then following up with using a legendary action to swallow a grappled PC will force the players to change up their fighting style or spend a high level spell to teleport out. Using the bite or swallow legendary actions consume two of the three actions it takes each round.
  • In a straightforward brawl it can use the legendary actions to make claw or tail swipes, functionally giving it eight attacks per round.

Be Willing To Go Off Book

Chaos Tarrasque
Chaos Tarrasque by Adam Vehige

Some groups will derive great satisfaction from developing an esoteric strategy from detailed in-character research. Other groups will have one player type “Tarrasque strategies” into google and discover that a clay golem is immune to all damage types the Tarrasque can deal. If this is something you’re worried about you can ask your players politely to not metagame the encounter you planned out and researched carefully, or you can shake up its ability set until they can’t just look up the correct kryptonite to use.

Another reason to go off book is that the Tarrasque can suffer as an endgame encounter because it is in its purest form a stack of hitpoints and a big attack modifier that hits you five times per round. Most legendary enemies have innate spellcasting, lair actions and status effects where the Tarrasque instead gets a bigger attack modifier. Running the fight purely as the Monster Manual is written can end up being a let-down if the players are used to more dynamic boss fights.

Here are some changes you can make to the Tarrasque and lore explanations for how it could come to be:




Allow its melee attacks to be considered magical.

The Tarrasque’s attacks bypass non-magical damage resistance and immunity.

The Tarrasque is already a deeply magical creature by nature with the way it resists almost all magics and can reflect spells back upon the casters. It doesn’t require any significant explanation to say that its own attacks are also magically augmented.

Allow it to maneuver more easily in a range of environments

The tarrasque can swim or burrow at its full movement speed, forcing the players to fight it on terrains they weren’t prepared for.

The original French mythology of the Tarrasque describes an amalgam of creatures including a large tortoiseshell and a mermaid like tail. Discrepancies between the Tarrasque players expect and the one they find can be attributed to convoluted mythologies and contradicting testimonies.

Give it a ranged attack or some way of dealing with flying enemies.

You have options for homebrew modifications you can make here, such as letting it belch its stomach acid as a cone attack, throw or kick rocks into the air, or shoot blood from its eyes like a horned lizard.

The most terrifying creature in Faerun’s mythology should not be so easily bested by an aarakocra with a crossbow. If it could be, somebody would have done it already.

Give it back the healing factor it had in previous editions

The Tarrasque regains 40 hitpoints at the start of its turn. For a level 20 party facing down the campaign ending threat, this much healing is within manageable levels, but the healing factor will disable most strategies for defeating it at earlier levels.

One of the most infamous traits of the Tarrasque in older editions of Dungeons & Dragons is that it doesn’t stay dead. In 3.5 edition this was represented by the creature regenerating hitpoints and having immunity to instant kill effects such as disintegrate.

Change its creature type from monstrosity to beast

By making it a beast it becomes eligible for a druid to cast Awaken on it, giving it sentience. A Tarrasque with humanoid level intellect is able to leverage its powers in very different ways. Teach it strategy. Enroll it at Strixhaven and teach it to cast spells as a level 30 creature with near complete immunity to enemy spellcasters.

The Monster Manual does not contain an explicit origin story. As DM you can decide it is a naturally occurring creature (beast) and not a wizard’s creation (monstrosity).

Include minions in the fight

Players are unable to penetrate the magic resistance or AC are still able to contribute. This can also reinforce the feeling of threat by demonstrating the impact on the world.

The Tarrasque might be followed in its rampage by opportunistic looters or heralded by a stampede of creatures trying to flee from it.

Abilities to interact with the environment

Give it some attacks that leverage its double damage versus buildings.

Allowing the Tarrasque to interact with the environment creates new options for the players in turn. An archer can use a tall building to extend their firing range and avoid direct attacks but risks harm if the Tarrasque knocks down the building beneath them.

Increase the movement speed by 20ft or more

Weakens strategies that boil down to “ride a horse at 40ft per turn while shooting it repeatedly”. Increasing the speed can also emphasize the threat it poses in other ways, such as by allowing it to retreat if wounded or even to ignore attackers entirely and focus on demolishing buildings.

The gargantuan sized creature should be able to outrun a horse the same way a human can outpace an ant.

You might also decide to weaken the Tarrasque in certain ways to tailor the fight to your group:

  • The ability to negate any spell utilising an attack roll forces spellcasters to play with a very narrow set of options in the battle which some groups may not enjoy. You might alter the reflective carapace ability to require a reaction, or have a limited number of uses.
  • If a player wants to climb it like they’re in Shadow of the Colossus, you may opt to waive the normal Dungeon Master’s Guide rules for climbing large creatures: These would allow the Tarrasque to dislodge any climbers with a single athletics check that is hard to fail with its 30 strength score.
  • You could allow researching players to discover a split in the reflective carapace caused by a previous battle. This would allow spellcasters to target the Tarrasque but only if they position themselves close enough to leverage that weakness.

Next: Hardest D&D Campaigns To Run

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