The tarrasque was first introduced to Dungeons & Dragons in 1983, appearing in the Monster Manual II book. A huge, lumbering reptilian beast, its hunger was legendary, its bite possessing the abilities of a sword of sharpness, so that there was a chance that any attack would sever a limb of the target, and its metallic hide would reflect spells such as lightning bolt and magic missile back at the caster, while negating any fire damage at all. This was a monster to be feared.

Or, at least, that was the theory.

The main trouble players have noticed with the tarrasque has generally been a simple one: it doesn’t fly. Thus, many gamers, upon encountering this “ultimate” monster, have engaged their various methods of flying, and pelted with magical arrows it from the air. The Tarrasque is a fantastic melee monster, but – even with its defenses – loses a lot of its interest if the players can just avoid it. The other trouble is in finding the right scenario in which it makes an appropriate enemy. It deserves a place as the final enemy, but it isn’t an intelligent foe; it won’t be the one planning the Ultimate Destruction of the Entire World™.

Encoded Design’s The Book of the Tarrasque endeavours to provide answers to these issues, bringing the tarrasque into the toolbox of DMs everywhere. It does this by discussing how best to use the tarrasque in combat, the adventures in which you might employ the tarrasque, and a suite of optional rules you can use to make the tarrasque an even more formidable foe. The book ends with a sample adventure about a doomsday cult who wish to use the tarrasque to bring about the Ultimate Destruction of the Entire World™.

The current version of the tarrasque lacks some of the traits that the original version has; I miss the severing bite, even though it gains the ability to swallow characters. John Arcadian, who wrote the advice in this book, provides a few more abilities you could give it: a lightning breath (taking inspiration from Japanese monster movies, such as Godzilla), the ability to fling rubble from ruined buildings at characters trying to fly, and restoring the regeneration ability that was rather significant in previous editions. Quite frankly, it needs them.

John is very obviously someone who loves the tarrasque, and the challenge it can present to higher-level characters. However, as he notes, some groups are just going to defeat the tarrasque in a short period of time, while others will experience the epic encounter wished for. A lot of the advice is based on his experiences through running battles against the tarrasque in convention play, although he also provides a few notes for campaign play. I very much appreciate the selection of twenty plot seeds that can be expanded into adventures or campaign play.

Chris Snieziak’s adventure, The Machine of Unmaking, is quite unusual in form. It is very obviously influenced by the other games Chris plays, podcasts about and occasionally writes for. Let me give you an example of its presentation:

The characters are summoned by a patron who reports that a friend from a neighbouring region has asked for help in dealing with the mythic beast known as the tarrasque. The patron wants the characters to see if the friend is telling the truth.

This way of providing iconic or important concepts – and emphasizing them in bold type – which can be replaced by specific people and places is a feature of a strand of games I’m not that familiar with; I know the Gumshoe system games have used it, I presume that others have as well (especially FATE). For a D&D Dungeon Master, used to having all the specific details written down, with names and places predefined (even if we then change them later to fit our campaign), it feels odd.

The adventure is presented using a short, four-act structure. In the first act, the players investigate a ruined city that the tarrasque has moved through. In the second act, they research in the library of the capital to discover what they’re up against (and might be attacked by cultists), the third act has them faced with challenges on the way to the final boss, and the fourth act, in the World’s End Mountains, sees the final confrontation against the cult (and, likely, the tarrasque).

It’s an effective adventure, and the use of a structure alien to existing D&D adventures allows us to see how else an investigation-style adventure can be formatted. The early D&D investigation adventures, such as The Assassin’s Knot, would have very much benefitted from a better structure. The rise of investigative scenarios in, primarily, tournament play has seen D&D expand its horizons beyond the dungeon adventures of its original form, and experimenting with the structures used by more investigative-led role-playing games in the D&D system is something well worth doing.

So, what do I think of the book? That’s a hard one, mainly because, as an experienced DM, a lot of the advice are things I already know about. The sections that focus on using the tarrasque in a one-shot adventure just designed to defeat it rather than in regular campaign play leave me cold, but I can see that they’ll be very useful for DMs preparing to use it in such a form. There are bits that I find pointless or problematic, such as the advice that says a party with items that confer flying is better equipped to fight the tarrasque – well, yes: those items actually create a major problem when using tarrasque-as-written. But there’s plenty of useful things in the book as well, and the addition of variant abilities (especially the throwing-rubble attack) does a lot to move the tarrasque back to the foe a well-prepared and equipped party will find challenging.

I really, really liked the notes on how the tarrasque has been used throughout the history of D&D, and its background as a French myth.

Ultimately, this is a book for a specific purpose: to encourage you to use the tarrasque in an exciting session or campaign. The fact that it includes an adventure that shows you one way to use the monster is a definite plus; the usefulness of the rest of the book will depend on the needs of the individual DM.