I really enjoy Pokémon minigames, and as soon as I unlocked Festival Plaza, I spent several hours inside. How-to guides are few and far between; serebii.net has a great resource, but what I really wanted to know was how to obtain maximal Festival Coins.
Festival Plaza is accessible in the bottom right of your menu after you reach the Pokémon Center in Hau'oli City, around the time you hit the Trainer's School.
Online battles, Wonder Trades, and the Global Trade System are all accessed through Festival Plaza. In addition, facilities can be bought and developed to dye clothes, train EVs, increase happiness, increase levels and more.
Enter Festival Plaza for the first time, and Sophocles will give you a short tutorial. Follow the tutorial, and you'll reach rank 4, where you can begin to participate in missions, and develop your Plaza into a useful resource.
Earning Festival Coins (FC) -- Guest Interactions
You can interact with visitors in your Festival Plaza to buy their clothes, or stores, or earn FC. Visitors with interactions that may earn FC will have a red speech bubble above their head, not the default blue. They may ask you to listen, tell, or direct them to a shop. For listening, and telling them about yourself, as far as I can tell, you do not earn more coins for the "right" answer, so answer truthfully (or not, whatever floats your boat).
When asked to direct visitors to a store, the visitor will give a hint as to the type of store they would like to visit. Unfortunately these are sometimes a little cryptic, so a complete list is as follows:
- "We're hungry. Take us to a yummy place" -- Restaurant; Rare Kitchen, Battle Table, Friendship Café, Friendship Parlor
- "I want to be excited. Take me to an exciting place"-- Haunted House; Ghosts' Den, Trick Room, Confuse Ray
- something good (skilled work?) -- Fortune Teller; Kanto Tent, Johto Tent, Hoenn Tent, Sinnoh Tent, Unova Tent, Kalos Tent, Pokémon House
- "Take me to a place that Pokémon can enjoy" -- Bouncy House; Clink-Clunk Land, Stomp-Stomp House, Phew-Phew Gym, Thump-Bump Park
- "Take me to a place you think I'd like" -- Lottery; Big Dreams, Gold Rush, Treasure Hunt
- "I want to shop. Will you recommend me a good place to shop?" -- Store; Ball Shop, General Store, Battle Store, Soft Drink Parlor, Pharmacy, Effort Shop
Sorry, I don't have the text/location for all interactions, so if you have it, please let me know and I'll update
Earning Festival Coins (FC) -- Missions
By far the most profitable way of earning FC however, is to participate in missions. After level 4 (21 FC) you can speak to a lady in front of the castle and obtain three Festival tickets a day. These tickets can be used to initiate missions, or if there is a red banner scrolling along the bottom screen, you can join an existing mission through local wireless or the internet. You earn FC based on your performance in the mission, as well as group performance. The most profitable mission early on is Type Matchup Tests. At most you can gain 50FC in one mission, if the group gets 5 stars (a group score of 350+) and you get 5 stars (an individual score of 15/16).
In Type Matchup Tests, you aim to find the supereffective move for any given type. Since you only have three minutes to get through as many people as possible, you should be aiming to scroll as little as possible. On the top are fire, water, electric, and grass, and on the bottom are fairy, steel, dark and dragon.
That is --
- Fire: Bug, Ice, Steel or Grass
- Water: Fire, Ground or Rock
- Electric: Water, Flying
- Fairy: Fighting, Dragon, or Dark
- Steel: Fairy
Other types should only be chosen if the secondary type is resistant to your first choice (e.g. Bug/Water, choose Electric which is more scrolling than Fire, but super effective)
With practice, an individual score of over 20 is fairly easy with Type Matchup. However, be sure to pick a time of day to play when more players are on, so as to maximise the group score as well.
Once you unlock Show off Muscles play that instead.
The FC gain from Show Off Muscles is maximally 60 for 2 minutes, as opposed to 50 for three minutes in Type Matchup. To gain points, it seems you want to be talking to people with positive phrases, however, there appears to be an element of randomness involved. These include:
- Bring it on
- oh, yes!
Earning Festival Coins (FC) -- Wonder Trade
Wonder trading inside the castle also spawns the visitor with whom you traded. u/Arcusico
The amount of coins per trade seems to be vary between players and ranges from 1FC to 8FC.
Spending Festival Coins -- Developing your Festival Plaza
I'm sure there are more things for you to spend coins on than you have coins. Nevertheless, I have some general recommendations. Every level up, enter the castle and speak to Sophocles. If you skip talking to him, and level up again, the previous prize store will no longer be available. He will give you the option of replacing an existing building with a new one. The good stuff in Festival Plaza only comes out for the higher levelled shops (more stars). As you level your plaza up to higher levels, the stores Sophocles offers you improve as well. If you're feeling generous, keep a high level/version specific store in your first slot, so that people who pass you can buy the store as well.
Generally one of each type is good, so as to have the correct store to send each visitor to. I personally wouldn't recommend buying stores from other players (once you reach level 8), unless they're really good, as if you continue visiting Sophocles he will properly deck our your festival, and you can keep your coins for something else.
Serebii suggests that it is possible to level up stores by buying from them, but I am unable to confirm. I would say for now the only way to obtain good stores is from levelling up your Plaza, or buying from other players.