Tier 2 D&D Modron Adventure: Time is a Construct

We’re back with another Side Quest! This time I’m showing some love to the misunderstood mechanical minions of Mecanus: Modrons! I wanted to try something a little different so this encounter is less of a dungeon-crawl and more of a race. Will the adventurers get the lost modrons home before they corrupt? Find out in this Tier 2 D&D Modron Adventure: Time is a Construct!

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Reference Resources Needed

Tier 2 D&D Modron Adventure: Time is a Construct

A Side Quest for 5th to 10th level adventurers


Once every 289 years, mechanical modrons from the realm of Mecanus embark upon a massive expedition of the Outer planes known as the Great Modron March. Thousands of these constructs form the vanguard of this march and follow the unseen directions of Primus, ruler of Mecanus. Learned scholars who track the modron’s cycle estimate that the next march won’t happen for another 100 years, however a modron splinter group has unknowingly started the march early and are now stranded on the Material plane.

Currently, the splinter group consists of eighteen remaining modrons: fifteen monodrones (the simplest of the constructs), two duodrones, and one quadrone left in charge. Without any higher modron in charge, the group established a small base camp near the edge of hill giant territory. Subsequently, the constructs putter around performing meaningless tasks while their limited energy supplies dwindle. It didn’t take long for the giants to notice trespassers in their domain, and now the modrons are in danger of being wiped out. It’s up to the adventurers to aid their return home before it’s too late.

Plot Hooks

  • Rumor has it that a strange campsite is situated a few miles outside of town. Small spherical creatures amble around a mechanical site, seemingly doing tasks at random and ignoring locals when approached.
  • The most observant in the party overhears the sound of combat beyond the trees, intermixing with an odd twittering sound. The roars and bellows of hill giants are unmistakable though.

Modrons Under Attack

The modrons have established a small circular base in a forest clearing. Using magics native to Mecanus, they erected a watchtower and guard walls to protect themselves and their dwindling supplies. The watchtower stands fifteen feet tall and has waist-high walls to allow the modrons to observe their surroundings. The camp and tower are all made from a strange metal alloy that looks as though it grew into place rather than assembled. Structures in the camp have an AC of 19 and 25 hit points. The camp is unlit normally except for two patches of glowing liquids smeared across the ground which provide dim light in a twenty-foot radius.

By the time the adventurers arrive, a hill giant attack is fully underway. Two hill giants (three if the adventurers are level 8 or higher) pummel modrons left and right, decimating their ranks. The giants each smash two modrons a turn while the duodrones and quadrone attempt to organize a resistance. Unless the adventurers intervene quickly, the giants eradicate the modron resistance within five rounds.

Attacking the giants splits their focus from the modrons, giving them a chance to regroup and retaliate. A coordinated effort from both parties is enough to drive off the giants, especially if one of the giants is slain.

If all of the modrons are slain before the giants are defeated, the adventurers find fine metallic powder (the dissolved remains of the modrons) scattered around the camp. Searching the camp yields twenty metallic javelins, six daggers, and a shortbow with twenty arrows. Nothing else remains of the modron party.

Construct Conversation

Once the giants are driven off (or slain), the modrons spend a moment to collect themselves and regroup, ready for another attack. The modrons only speak in a confusing sequence of beeps and trills, but if none of the adventurers can communicate with the creatures, the quadrone approaches holding a platinum medallion which it taps to its forehead. The quadrone then speaks in a clear, (if a bit mechanical) common language and introduces itself as “QU-9854-RK” (or Quark).

Quark quells the lesser modrons and thanks the adventures for intervening, but explains that they are currently stranded upon the material plane. Quark also points over to a puddle of smashed glass containers and glowing liquid and explains that while modrons do not require food or drink, their “energy supply” was destroyed during the giant attack. Without a proper energy source from Mecanus, the modrons will “degrade” within days. With this in mind, the adventurers need to find a way to get the constructs home, otherwise this minor march will have an ignoble end.

Locating a Spellcaster

If the adventurers don’t know any spellcasters able to open a planar gate for the modrons, then they’ll have to spend time searching. Depending on the setting, finding a powerful enough spellcaster will be easier or harder. Consult the following table for search times and DC:

  • Rural locale: The adventures may make one DC 17 Intelligence (Arcana or History) per day of search and find a spellcaster after the fourth successful check.
  • Small town: The adventures may make one DC 16 Intelligence (Arcana or History) per day of search and find a spellcaster after the fourth successful check.
  • Large town: The adventures may make one DC 16 Intelligence (Arcana or History) per day of search and find a spellcaster after the third successful check.
  • Small city: The adventures may make one DC 15 Intelligence (Arcana or History) per day of search and find a spellcaster after the third successful check.
  • Large city: The adventures may make one DC 15 Intelligence (Arcana or History) per day of search and find a spellcaster after the second successful check.
  • Metropolis: The adventures may make one DC 14 Intelligence (Arcana or History) per day of search and find a spellcaster after the second successful check.

The adventurers find an archmage named Celaena Ara’faelin (Female Elf Neutral good) who can perform the spell gate for the modrons. While the mage is happy to aid the group, she does require a fee of 6,000 gold pieces to cast the spell. If the price is too steep, the adventurers may appeal to Celaena’s good side by explaining the situation with the modrons, allowing a DC 14 Charisma (Persuasion) check. On a success she offers to perform the spell for free, but will ask the adventurers for a favor in the future.

With their magical transportation secured, Quark and the remaining modrons thank the adventurers by leaving them their medallion of inter-planar communication (see below).

Modron Time Constraint

With limited resources, the modrons have a week at best before they begin irreparably degrading. If the adventurers take longer than a week to succeed in getting the modrons back to Mecanus, roll a d20 each day to see how badly they degrade. Add +1 to the roll for each day past the first week.

  • 1-5: The modrons have trouble communicating with each other, but otherwise act normally.
  • 6-10: The modrons begin losing critical functions but can still operate – Modrons cannot take reactions or bonus actions.
  • 11-15: Sluggish processors slow the modrons down significantly – Reduce all modron’s walking speeds by half, and all fly speeds to 0 ft.
  • 16-19: Corrupted synapses cause the modrons to confuse allies for enemies! Roll a d6 on each modron’s turn: on a 1-4 the modron uses its turn to attack an ally, 5-6 the modron acts normally.

20+: Complete and utter shutdown. The modron ceases all activity and goes into an inert state until returned to Mecanus.

Hill Giant Revenge

If the adventurers hang around too long near the area where the modrons were found, there’s a chance that any surviving hill giants regroup and attack! Roll a d6 each day the adventurers remain within 5 miles of the modron camp:

  • d1-3. The giants are unable to track down the party, but add +1 to subsequent rolls.
  • d4-6. 2-3 hill giants ambush the adventures! These giants separate their attacks between the adventurers and the remaining modrons, and will only retreat if reduced to less than a quarter HP.

Appendix - Magic Items

Medallion of inter-planar communication

Wondrous Item, Rare (requires attunement)

The platinum medallion, emblazoned with an intricate cog system to represent Mecanus, has 3 charges. While wearing it, you can use an action and expend 1 charge to cast the comprehend languages spell or 3 charges to cast the tongues spell from it. The medallion regains 1d2 expended charges daily at dawn. If the wielder is slain, the medallion disintegrates into dust.

Wrap up

That brings us to the end of this adventure! Did your party save Quark and the other modrons, or did they become mangled machinery mash under the clubs of the hill giants? If you liked this Tier 2 D&D Modron adventure, feel free to leave a comment below or drop a comment on Twitter, Facebook, Instagram, or Discord to let us know how it went! If you’d like access to more maps and content, including downloadable PDFs of our adventures, check out our Patreon. We’re able to do what we do because of all our amazing Patron

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