Fasnacht Day

Fasnacht Day, otherwise known as Fasnacht Parade, is a seasonal public event

Detailed walkthrough
To start the event, speak to the Master of Ceremonies in Helvetia at the top of the real-life hour (at XX:00). He'll be hanging around the bridge over the small creek that runs through town near the east side of it. There's about a 9-10 minute grace period to speak to him before the event is automatically failed if he is not spoken to beforehand. Once started, the vault dwellers involved in the event must find five of the eight randomly-assigned Protectron marchers that can spawn in the town. Each Protectron will provide a task corresponding to their profession, and each task must be completed before the parade can begin. After a task is finished, the relevant marcher will walk to the center of town, equip its Fasnacht mask, and wait for the others to arrive. The possible Protectrons and corresponding tasks are as follows:
 * Cheerful Beekeeper: Exterminate the honey beasts which are attacking the Honey Haus. There are usually three basic honey beasts that need to be dealt with.
 * Happy Candlemaker: Donate beeswax from the Honey Haus hives to the Candlemaker (0/10)
 * Gleeful Butcher: Donate intestines from small animals at the Butcher's Cooler (0/12)
 * Jolly Baker: Donate radtoad eggs from the stream to the Pantry (0/20)
 * Convivial Historian: Bring old Fasnacht steins to the museum for analysis (0/10)
 * Joyous Musician: Play one of the three instruments, found on the stage, in order to fill the meter.
 * Jubilant Decorator: Decorate the barn (0/4)
 * Merry Woodsman: Add wood to the bonfire (0/50)

Once all five tasks are completed and all five Protectrons assemble in the center of town, the Master of Ceremonies rushes over to join them and take point as parade leader, and the parade begins its route. First, the group walks east down Pickens Rd. to the front of Freyja's Haus, the yellow-painted restaurant, where it is attacked by swarms of radtoads. The Protectrons can sometimes handle these on their own, depending on which ones spawned for the event. After the creatures are eliminated, the group moves north over the wooden bridge toward the Cheese Haus. The marchers stop in the middle of the field as super mutants, mutant hounds, and super mutant suiciders charge the group, with the suiciders being the biggest threat to the Protectrons if they get close enough to damage them when they detonate their mini nukes. Once the mutant assault has stopped, the marchers continue south. Finally, when the parade stops in front of the chapel, hordes of stingwings and wolves attack. A legendary mega sloth also spawns near the post office. The enemies spawn and attack when the music played by the Master of Ceremonies abruptly slows and stops before recovering, but playing a faster tempo during the attack, then repeats once the attack is over and the parade resumes, with the tempo returning to normal speed.

After the enemies have been killed, the Fasnacht bonfire must be lit. At least one Protectron marcher needs to be kept alive in order to complete the event, with more survivors netting greater rewards, otherwise, if all five are slain, the quest fails. The participants may also be granted a random legendary weapon or armor piece after the quest is completed. Completing the event also awards at least one random Fasnacht mask as a reward.

Rewards

 * Note: Listed chances assume 5/5 robots survive.

Availability
This limited time event was first available from March 19–26, 2019. It returned from May 27, 2020 to June 9, 2020. The quest returned for a third time as a Halloween event, every hour on the hour from 12:00 p.m. ET October 29, 2020 to 12:00 p.m. ET November 2, 2020. It returned once more for a fourth time, on February 16, 2021 and was originally scheduled to last until February 22. However, it was later extended to February 25. . It returned for a fifth time, running from February 10-22, 2022.

Delays
Fasnacht Day's return in 2020 was initially delayed due to a bug introduced with the release of Wastelanders. The event was originally slated to be active from May 25 - June 1, 2020, but a bug prevented small creatures from spawning at normal rates on public servers. Since intestines, dropped by small animals, could not be obtained but were needed for the Gleeful Butcher's parade task, the event could not be completed without prior preparation.

The event was disabled on the morning of May 25, having only briefly been active before being delayed. The issue was not present during the 2019 version of the event and the critters bug was confirmed to have been introduced with Wastelanders. Fasnacht Day was eventually re-enabled without major issue on May 27, with an extension of the festivities until June 9.

Bugs

 * The Fasnacht Day parade music may not play until the first Defend objective appears.
 * Defeat Honey Beasts at the Honey Haus: honey beasts may spawn behind the Cheese Haus, and will not move until they detect a player.
 * Porcelain Stein: porcelain steins are missing their auto-scrap protection.
 * Destroyed Marchers (#/5): Protectron marchers may be destroyed by explosive bait.

Behind the scenes

 * Fastnacht is an annual carnival celebrated by Swiss and German people while traditionally wearing masks that represent demons, jesters, witches and animals. In Helvetia, West Virginia it is normally celebrated once per year on the first weekend after Fat Tuesday, and concludes with the burning of an effigy in a bonfire, without any robots or megasloths.
 * The music played during the Fasnacht parade is the 2004 One More Pils instrumental exercise composed by Andy Vale and licensed from APM Music. While the original piece is 1:10 minutes long, the version used in-game is comprised of two 15 second clips that endlessly repeat one after another.