Following are D&D 5E rules that can be used to adjudicate attempts by characters to votively replicate Hercules’ tenth labor, which included a battle with the three-headed giant Geryon and then driving his herd of cattle from Iberia and the western Mediterranean back to Greece. This challenge takes place at Megalos Ellada, a large farm on the Peloponnesian Peninsula of mainland Greece and one of the places that appears in Skirmisher Publishing’s “In the Footsteps of Hercules” universal sourcebook. It is most suitable for characters of 1st to 4th level.

This is the second and most complex of the four related challenges characters can undertake over the course of a festival day at the farm and takes place mid-morning. It follows Riding the Bulls of Crete and precedes Stealing the Apples of the Hesperides and Battling the Mares of Diomides. 

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Battling “Geryon”

As described in the sourcebook, a party participating in this challenge will be led to a 25-foot-tall contraption that has been created from a windmill and which has the image of a monstrous, six-armed giant painted on its side; a rotating vertical wheel with three spokes that project from the chest of the “giant” and has a large round shield affixed to the end of each; and a rotating horizontal platform with three painted ceramic heads affixed to it at its top. It is no longer driven by wind and is instead powered by a mechanism in the adjacent Alpheus River.

Characters must defeat “Geryon” by shattering the ceramic heads with missile attacks and, when all three have been destroyed, the reduced weight on the device will cause a clockwork mechanism to open the gate, beyond which is the herd of cattle. At least half of the party must participate in this portion of the challenge, and those not very adept with missile weapons can use their actions to spot for others and grant them advantage on their attacks.

Each of the three rotating heads mounted at the top of the repurposed windmill has an Armor Class of 17 (10 + 4 for their movement by the device +3 for the spinning shields). Any missiles fired at a head that misses by one, two, or three places will strike one of the shields, which will clang like a gong and agitate the cattle. Each head has 7 hit points, vulnerability to bludgeoning damage, and upon being reduced to 0 hit points will shatter, causing the water in it to gush out. Default range for the challenge is 40 feet.

Characters can also do things to slow down the spinning of the shields and rotation of the heads and make them more easy to hit. Any round in which Create or Destroy Water is used to destroy water powering the mechanism it will be slowed and the AC of the heads reduced by 2, and if Gust of Wind is used to slow the rotation of the heads their AC will be reduced by 3. Storytellers can adjudicate other effects as appropriate.

If characters do anything to actually damage or destroy the device, such as attack the mechanism with melee weapons or set it on fire, the proprietors will disqualify them from the event.

Herding the Cattle

For every character in the party there will be 10 cattle in the herd that they must drive a distance of about two-thirds of a mile, first away from the banks of the river; then across a stretch of pasture; and then up a ravine and to a meadow in the hills. This process will probably take 10 or 15 minutes altogether. Characters have a lot of leeway in what they do to accomplish this task but those who actually harm any of the cattle will be disqualified (and might suffer other repercussions as well).

Each party member participating in the cattle drive can make a Wisdom (Animal Handling) check during each of the three phases of the drive. For every place a character scores above 10, he or she succeeds at moving one beast and keeping it with the herd (e.g., a total result of 19 means a character is responsible for successfully herding nine cattle during a particular phase).

A character who during the second or third phase of the challenge goes after “strays” who got left behind or wandered off will only be able to herd half as many as they would with a particular roll.

* Characters have -1 on this check for each time one of the shields was struck during the “battle with Geryon” (e.g., -3 if it was struck three times).

* Characters who are size Large have advantage on this check and those who are mounted can add the Strength bonus of the creature they are riding to it (e.g., +5 for a Str 19 warhorse). Storytellers can apply other effects as appropriate (e.g., a character with a trained dog as a companion might receive advantage on their checks).

* Characters can use appropriate spells or abilities to enhance chances of success and, because each phase represents several minutes of time, a storyteller might allow multiple usages (e.g., a Cleric might apply Guidance to each of the checks made by her and her companions, a Bard might grant Bardic Inspiration to separate characters as many times as he is able).

* A character who rolls a natural “20” on a check will move 10 more cattle than would be normal for the results of their roll (five more if they are going after strays).

* A character who rolls a natural “1” will be attacked by one of the cattle.

* During the second phase, if the character party seems to be doing too well, a troublesome person among the spectators — e.g., a priestess of Hera, a malicious sorcerer — will summon an Infernal Gadfly to harass one of the characters and the cattle they are herding. This will cause the character to suffer disadvantage on his or her Wisdom (Animal Handling) check during that phase (and, if desired, the storyteller can adjudicate combat between the character and the monster).

* During the third phase, where the trail approaches a gap between two small hills, some 1d6+5 cattle might break away into an adjacent stand of woods, which characters who succeed at a DC 16 Wisdom (Perception) check will notice (those on the right side of the herd will make this check normally, those behind or ahead at disadvantage, and those to the left cannot make it at all). A character who sees the cattle slipping away and chases them can use their Wisdom (Animal Handling) check for the phase to attempt to drive as many of them as possible back to the herd. They will also have the encounter described in the “In the Footsteps of Hercules” sourcebook!

Suggested XP for this challenge is 70 XP for each head of cattle successfully driven to the meadow at end of the course, totaled and then evenly divided among all participating characters.

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Cattle of Geryon

This shaggy, unruly creature may be descended from one of those that was once owned by the giant Geryon and driven from Iberia to Greece by Hercules. Such animals are not overly aggressive but may turn on people who irritate them, possibly goring, knocking over, and stomping on those they knock prone.

Cattle of Geryon

Large beast, unaligned

Armor Class: 11

Hit Points: 22 (3d10+6)

Speed: 40 ft.

STR             DEX             CON             INT               WIS              CHA

18 (+4)         12 (+1)         14 (+2)         2 (-4)            11 (+0)         7 (-2)

Senses: Passive Perception 10

Languages: —

Challenge: 1/2 (100 XP)

Trampling Charge. If the cattle moves at least 20 feet straight toward a creature and then hits it with a gore attack on the same turn, that target must succeed on a DC 14 Strength saving throw or be knocked prone. If the target is prone, the cattle can make one stomp attack against it as a bonus action.

ACTIONS

Gore. Melee Weapon Attack: +6 to hit, reach 5 ft., one target. Hit: 11 (2d6+4) piercing damage.

Stomp. Melee Weapon Attack: +6 to hit, reach 5 ft., one prone creature. Hit: 11 (2d6+4) bludgeoning damage.

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Infernal Gadfly

Native to the wastes of gloomy Tartarus, these malicious fiends look like fat flies and relish tormenting people and animals alike. They sometimes serve as familiars to especially loathsome masters or are summoned by spellcasters to harass or distract their foes.

Infernal Gadfly

Tiny fiend (Tarterian), neutral evil

Armor Class: 14

Hit Points: 5 (2d4)

Speed: 10 ft., fly 60 ft.

STR             DEX             CON             INT               WIS              CHA

2 (-4)           18 (+4)         10 (+0)         3 (-4)            11 (+0)         5 (-3)

Damage Resistances: Cold, fire, lightning; bludgeoning, piercing, and slashing from nonmagical attacks

Damage Immunities: Poison

Condition Immunities: Poisoned

Senses: Darkvision 120 ft., Passive Perception 10

Languages: —

Challenge: 1/4 (50 XP)

Magic Resistance. An Infernal Gadfly has advantage on saving throws against spells and other magical effects.

ACTIONS

Bite. Melee Weapon Attack: +6 to hit, reach 5 ft., one target. Hit: 1 piercing damage, and the target suffers disadvantage on all attacks and skill checks until the beginning of the Infernal Gadfly’s next turn.