Biorhythm (Japanese:バイオリズムbiorhythm) is a mechanic applied tounits which simulates how an individual's ability to fight to their fullest potential fluctuates as time goes on, making them perform better at some times and perform worse at others. A unit's biorhythm follows a pattern shaped like asine wave, advancing along the wave a little bit periodically, and as it follows the ups and downs of this wave, the biorhythm give bonuses or penalties to the unit'saccuracy andevasive ability during the course of a battle.

At any given time, a unit's biorhythm puts them in one of five states: Best, Good, Normal, Bad, and Worst. A Good state or higher gives the unit small hit and avoid boosts, while a Bad state or lower gives small penalties to the same. The biorhythm chart can be viewed in each unit's stat screen to see their current state and where the biorhythm will put them in later turns, and their current biorhythm state is shown on the map when hovering the cursor over them, indicated by red and green arrows.

Biorhythm is only present inFire Emblem: Path of Radiance andRadiant Dawn.

Fire Emblem: Path of Radiance

Biorhythm pattern

InFire Emblem: Path of Radiance, all units share the same biorhythm wave. Biorhythm moves in a 30-point cycle, after which it restarts from the beginning of the wave.

Biorhythm moves under two conditions:

• For every 10 rounds of attack the unit participates in (regardless of whether they initiate it or are capable of counterattacking), their biorhythm moves forward by one point.
• For every chapter they participate in that gets cleared, their biorhythm moves forward by seven points. The four parts ofChapter 17 are not treated as individual chapters for the purposes of biorhythm advancement, butthe second part of Chapter 27 is treated as a separate chapter.

Almost all units, both playable and enemy, will start a map with their biorhythm at a completely random point, with the point being reset every time the player resets the game. However, several early-game units (10 playable, 2 bosses) will have their biorhythm start at a pre-set point when they first appear in their debut chapter.

In terms of how this is handled internally, these starting biorhythms are actually counted up from how many chapters have elapsed since the "first chapter" in terms of the game's internal storage, which is actuallythe debug map, with the Prologue being counted as #2 and the rest of the game's chapters proceeding from there. For instance, Mia's starting biorhythm is actually stored as 12 (Good), but since the player has progressed through eight chapters (counted as including the debug menu) by the time she first appears, the seven points awarded by clearing a chapter are applied eight times, bringing her to start with her biorhythm at 8 (Good).^[1]

Calculations

The five biorhythm states award the following bonuses

• Good: +5 hit rate, +5 avoid
• Normal: No effect
• Bad: −5 hit rate, −5 avoid

Skills affecting biorhythm

Skills affecting biorhythm
	Item	Effect	Games
	Tempest	Doubles biorhythm effects.	Path of Radiance
	Serenity	Halves biorhythm effects.	Path of Radiance

Fire Emblem: Radiant Dawn

Biorhythm patterns

There are ten different biorhythm waves inFire Emblem: Radiant Dawn, two of which are exclusive to enemy bosses. Playable units and major enemies are all assigned one specific biorhythm pattern, while generic enemies are assigned biorhythms at random (excluding types 8 and 9). All waves move through a 25-point cycle, after which it restarts from the beginning of the wave. Every unit joins with their biorhythm starting at 1 regardless of their starting affiliation, and it advances at the end of their army's phase—for example, an enemy unit will change biorhythm at the end of enemy phase. A unit's biorhythm state is kept from map to map; for example,Zihark will joinPart 1, Chapter 6 with his biorhythm set at 6, since he spent 5 turns as a green unit inPart 1, Chapter 5, and that chapter's ending trigger occurs before the biorhythm trigger. Meanwhile,Volug in the same chapter will be at 7 since he had 6 player phase end turns.Elincia will always startPart 2, Endgame at bad biorhythm, which will then become worst on the first turn of enemy phase.

Type 0

The type 0 biorhythm is a standard pattern, comparable to thePath of Radiance pattern. It is found on nine playable units, five bosses, and one NPC.

Player	Nolan	Vika	Elincia	Oscar	Ranulf	Sigrun	Stefan	Caineghis	Kurthnaga
Bosses and NPCs	Isaiya	Kurth	Burton	Callum	Yuma

Type 1

The type 1 biorhythm has very long Best and Worst points. It is found on nine playable units, five bosses, and one NPC.

Player	Micaiah	Aran	Volug	Zihark	Leanne	Brom	Makalov	Astrid	Rhys	Tanith
Bosses and NPCs	Zaitan	Djur	Istvan	Zelgius	Roark	Black Knight

Type 2

The type 2 biorhythm has relatively stable and minor effects on units' stats, having neither Best nor Worst points. It is found on nine playable units and three bosses.

Player	Leonardo	Tauroneo	Muarim	Marcia	Nephenee	Ulki	Naesala	Pelleas	Nasir
Bosses and NPCs	Agony	Tashoria	Levail

Type 3

The type 3 biorhythm is somewhat erratic, spending relatively little time at Normal, Good, or Bad points. It is found on six playable units, five bosses, and one NPC.

Player	Heather	Kieran	Boyd	Lyre	Skrimir	Oliver
Bosses and NPCs	Aimee	Pain	Rommit	Sergei	Valtome	Lekain

Type 4

The type 4 biorhythm is very erratic and rapidly plunges between Best and Worst points. It is found on five playable units and seven bosses.

Player	Jill	Calill	Soren	Shinon	Kyza
Bosses and NPCs	Pugo	Wystan	Yeardley	Septimus	Numida	Izuka	Hetzel

Type 5

The type 5 biorhythm is somewhat erratic, spending relatively little time at Normal, Good, or Bad points. It is found on thirteen playable units and three bosses.

Player	Edward	Tormod	Nealuchi	Lethe	Mordecai	Geoffrey	Titania	Mist	Mia	Gatrie	Reyson	Janaff	Sanaki
Bosses and NPCs	Zeffren	Ludveck	Kezhda

Type 6

The type 6 biorhythm is very stable, having neither Best nor Worst points and spending long periods of time in Good and Bad states. It is found on nine playable units and three bosses.

Player	Sothe	Ilyana	Fiona	Rafiel	Haar	Bastian	Volke	Giffca	Ena	Lehran
Bosses and NPCs	Maraj	Lombroso	Dheginsea	Sephiran

Type 7

The type 7 biorhythm has very long Best and Worst points and sharply shifts between them. It is found on ten playable units and one boss.

Player	Laura	Meg	Nailah	Lucia	Danved	Ike	Rolf	Tibarn	Renning	Gareth
Bosses and NPCs	Laverton

Type 8

The type 8 biorhythm is completely neutral and gives no bonuses or penalties whatseover. It is exclusive to enemy bosses.

Bosses and NPCs	Radmin	Silvano	Catalena	Ashera

Type 9

The type 9 biorhythm is similar to type 0, except it never enters Worst points. It is exclusive to enemy bosses.

Bosses and NPCs	Jarod	Veyona	Goran

Calculations

The five biorhythm states award the following bonuses

• Best: +10 hit rate, +10 avoid, +10% chance of triggeringskills, +20% chance of successfully recoveringhidden treasure
• Good: +5 hit rate, +5 avoid, +5% chance of triggeringskills, +10% chance of successfully recoveringhidden treasure
• Normal: No effect
• Bad: −5 hit rate, −5 avoid, −5% chance of triggeringskills, −10% chance of successfully recoveringhidden treasure
• Worst: −10 hit rate, −10 avoid, −10% chance of triggeringskills, −20% chance of successfully recoveringhidden treasure

Items and skills affecting biorhythm

Items and skills affecting biorhythm
	Item	Effect	Games
	Matrona	A staff that restores all HP to a distant target. It also raises the target's biorhythm to its peak.	Radiant Dawn
	Galdrar	Bliss: Raise biorhythm to its highest point. Sorrow: Lower biorhythm to its lowest point.	Radiant Dawn

Flavor text

Trivia

• Although biorhythm as a mechanic is absent in all games afterRadiant Dawn, the Japanese names of the skillsOdd Rhythm andEven Rhythm fromAwakening refer to it and have similar effects, although their effects work on a much smaller scale.

Etymology and other languages

Gallery

• 
  Mia's biorhythm chart inPath of Radiance. She is currently at Good status.
• 
  Nolan's biorhythm chart inRadiant Dawn.
• 
  InRadiant Dawn,Edward's current state (Best) is indicated by a green arrow in the corner of his HP box.

References