The Fes Portion of the game is one of three main activities which you can do in the game. (The other two being producing idols and sending supports to work.) The Fes portion is similar to auditions and wing in that the main objective is to appease all three judges and obtain the most amount of stars without your mental dropping to zero. Unlike auditions and wing, your team composition is based upon the fes idols that you have on hand, and the overall stats of your team will be dependent on your team members. In this mode, you can battle against the AI through Fes Rehearsal you can also indirectly challenge other players' fes units through Grade Fes.
The image above shows the fes lobby. The trending stats for the current time period is shown on the top part of the page (1). If a fes event is on-going, the units that have a bonus will be displayed on the top left. Three small buttons on the bottom are for showing rewards for grade fes (7), a shortcut to the money shop (8), and the fes unit composition page respectively (9).
The design of the lobby can change depending on your current grade. The current grade and whether or not you will grade up, grade down, or maintain your current grade is displayed on the left side of the page (2). Below it is your current highest grade fes score (3). Below that is the score threshold for you to surpass in order to maintain your current rank or rank up (5). Further below is the current number of players that are in this grade and Below that is your current ranking (5).
The huge pink button is where you click to play fes, clicking it will give you an option between fes rehearsal (フェスレハーサル) or grade fes (グレードフェス). Participating in either fes will cost one fes entry, represented by the small yellow marks at the bottom of the play button on both the home screen and the fes lobby. Fes entries will recover over time at a rate of one per half hour up to a maximum of five. Entries can also be instantly restored by using a consumable fes entry ticket item.
Upon pressing the fes unit composition button, the screen above should appear featuring your current unit. You can have up to 10 units, each having 5 members each. Each member specializes in a specific attribute, similar to how live party units work in Starlight Stage. Idols at the center will have 50% increase in all stats except mental. while each of the three slots reserved for an attribute (vocal, dance, visual) will have 100% bonus to that specific attribute. The Leader slot is special because not only does it give 100% bonus to mental, it's also gives 50% increased chance to proc it's passive skills. The memory appeal level of the unit is determined by the center's memory appeal, while a bonus multiplier is determined by the memory appeal levels of the other 4 members.
If the unit contains all the members of a particular unit (3 members for Illumination Stars/Alstroemeria, 5 members for L'antica and Houkago Climax Girls), all the members of that particular unit will receive a 20% boost to all stats. Also, during fes events, specific units can have bonuses to stats for a given time period during the duration of the event.
The rank of your fes unit varies depending on a variety of factors including, total appeals, what appeal skills your unit members have, and the passives the unit members have learned.
In fes rehearsal, players get to fight against AI bots with pre-determined stats and skills based on the difficulty. Players can choose the difficulty of the bots after selecting fes rehearsal. There are three difficulties: Easy, Normal and Hard, each with their own money multiplier. By checking the box at the lower right of the screen the player can expend all remaining fes entries at once in exchange for a money multiplier equal to the number of entries used. During Fes Events, a Very Hard difficulty is unlocked, featuring bots with high mental and appeal scores, and judges with high mental and can hurt your mental more than usual.
The AI also has a set pattern depending on the difficulty, much like in auditions. The opponents do not use special skills and their stats as well as the stats of the judges are reliant on the difficulty selected. Players will definitely have to rely on their fes unit's stats, skills and passive to win them the fes.
Grade Fes is also AI controlled, but instead of using bots with pre-determined stats, it uses player data and teams. This means that card appeal skills and fes idol passives will also activate during grade fes. Much like fes rehearsal, it has easy, normal and hard difficulties, but the very hard difficulty does not show up during fes events.
The strength of the judges in these three difficulties is also dependent on what grade you are at the moment. The higher the grade the tougher the judges, meaning more mental and more damage that they can deal. Also, your opponents can have much stronger teams as you rise up the ranks, so team building is very crucial for grade fes.
While both grade fes and fes rehearsals give random tension values to your team and to your opponents, grade fes has a specific interface for it prior to starting the fes proper:
The screen on the left shows the center of your unit, a list of you alongside the five rivals. The pink button on the bottom left starts the tension roulette. There are 5 possible results, as seen on the right. The red very happy face gives off the highest charge for the memory appeal bar, while the purple very sad face forces the player to start fes with no charge in the memory appeal bar. From highest to lowest memory appeal gauge, the tension faces go as follows: red (very happy) -> yellow -> green -> blue -> purple (very sad). This is randomly generated.
Regardless of whether or not it is a fes rehearsal or grade fes, the interface of the fes screen itself is exactly similar to auditions.