Ary

Without further ado, here is an updated episode guide containing all the AT episodes that contain major plot, important backstory, and/or Bubbline moments. I have also included optional episodes that I think will increase your understanding/enjoyment of the show (I put the reason next to it; if it says something about being an arc, backstory, etc., be warned that not watching may make major plot points of the show a bit more confusing.)

I have condensed the show down from 279 to 181 of the 10-minute episodes (only 100 if you skip all the optional episodes). 

Once again, optional episodes are in italics. Episodes with Bubbline moments, characterization and/or major backstory/plot related to Marcy/PB are in bold. Anything with a an asterisk (*) can be watched at any time (order doesn’t matter, though you may still want to watch it in the same season). I hope you enjoy! 

Season 1

1 x 2 “Trouble in Lumpy Space” | Introduces LSP

1 x 3 “Prisoners of Love” | Introduces the Ice King

1 x 5 “The Enchiridion”

1 x 9 “My Two Favorite People” | Introduces Jake & Lady Rainacorn (LR) arc

1 x 10 “Memories of Boom Boom Mountain”

1 x 12 “Evicted”

1 x 15 “What is Life?” | Introduces NEPTR + Ice King characterization

1 x 16 “Ocean of Fear” | Finn characterization

1 x 17 “When Wedding Bells Thaw” | Ice King characterization

1 x 20 “Freak City” | Introduces Magic Man

1 x 22 “Henchman”

1 x 24 “What Have You Done?” | Ice King characterization (*)

1 x 25 “His Hero”

Season 2

2 x 1 “It Came from the Nightosphere”

2 x 2 “The Eyes” | Ice King characterization

2 x 3 “Loyalty to the King” | Ice King characterization

2 x 7 “Power Animal” | Establishes more of Adventure Time universe

2 x 10 “To Cut a Woman’s Hair”

2 x 11 “Chamber of Frozen Blades” | Ice King characterization (*)

2 x 12 “Her Parents” | Jake and Lady Rainacorn (LR) arc

2 x 15 “The Real You”

2 x 17 “Death in Bloom” | Establishes more of the AT universe

2 x 18 “Susan Strong” | Introduces Susan Strong arc

2 x 20 “Go with Me” | Subtle Bubbline

2 x 24 “Mortal Folly”

2 x 25 “Mortal Recoil”

2 x 26 “Heat Signature”

Season 3

3 x 3 “Memory of a Memory”

3 x 5 “Too Young”

3 x 6 “The Monster” | LSP characterization/general cuteness (*)

3 x 7 “Still” | Ice King characterization

3 x 9 “Fiona and Cake” | Gender bending episode (*)

3 x 10 “What was Missing”

3 x 14 “Beautopia” | Susan Strong arc continues

3 x 17 “Thank You” | Not vital to plot, but adorable (*)

3 x 18 “Apple Thief” | Not vital to plot, but a favorite (*)

3 x 19 “Holly Jolly Secrets Pt. 1”

3 X 20 “Holly Jolly Secrets Pt. 2″

3 x 21 “Marceline’s Closet”

3 x 25 “Dad’s Dungeon” | Finn and Jake background

3 x 26 “Incendium” | Flame Princess arc 

Season 4

4 x 1 “Hot to the Touch” | Flame Princess arc

4 x 2 “Five Short Graybles” | Established more of AT universe (*)

4 x 5 “Return to the Nightsophere”

4 x 6 “Daddy’s Little Monster”

4 x 8 “Hug Wolf” | Generally cute (*)

4 x 9 “Princess Monster Wife” | Ice King characterization + great episode

4 x 10 Goliad

4 x 11 “Beyond this Earthly Realm” | Ice King characterization

4 x 13 “Princess Cookie” | Generally cute

4 x 15 “Sons of Mars” | Established more of AT universe

4 x 16 “Burning Low” | Flame Princess arc + PB characterization

4 x 18 “King Worm” | Serious foreshadowing

4 x 19 “Lady and Peebles”

4 x 20 “You Made Me”

4 x 22 “Ignition Point” | Flame Princess Arc

4 x 23 “Reign of Gunters”

4 x 24 “I Remember You"

4 x 26 “The Lich”

Season 5

5 x 1 “Finn the Human”

5 x 2 “Jake the Dog”

5 x 6 “Jake the Dad” | Jake/LR arc

5 x 5 “All the Little People” | Cool and very slight Bubbline cameo

5 x 9 “All Your Fault”

5 x 11 “Bad Little Boy” | Gender bending + Marcy/Ice King development

5 x 12 “Vault of Bones” | Flame Princess arc

5 x 14 “Simon and Marcy”

5 x 16 “Puhoy” | Flame Princess arc

5 x 17 “BMO Lost” | SO ADORABLE. If you don’t watch you’re missing out (*)

5 x 18 “Princess Potluck” | Ice King characterization (*)

5 x 20 “Shh!” | Established more AT universe and is cute/neat (*)

5 x 21 “The Suitor”

5 x 22 “The Party’s Over, Isla de Senorita” | Ice King character development

5 x 23 “One Last Job” | Jake character development

5 x 26 “Wizards Only, Fools”

5 x 28 “Be More” | BMO backstory (*)

5 x 29 “Sky Witch”

5 x 30 “Frost and Fire” | Flame Princess arc

5 x 31 “Too Old”

5 x 32 “Earth and Water”

5 x 33 “Time Sandwich”

5 x 34 “The Vault"

5 x 38 “Red Starved”

5 x 40 “Play Date” | Finn character development

5 x 41 “The Pit” | Finn character development

5 x 45 “Blade of Grass”

5 x 46 “Rattleballs” | Finn character development

5 x 47 “The Red Throne” | Flame Princess arc

5 x 48 “Betty”

5 x 50 “Lemonhope Pt. 1″

5 x 51 “Lemonhope Pt. 2″

5 x 52 “Billy’s Bucket List”

Season 6

6 x 1 “Wake Up”

6 x 2 “Escape from the Citadel”

6 x 4 “The Tower” | Finn character development

6 x 6 “Breezy”

6 x 9 “The Prince Who Wanted Everything | Gender bending (*)

6 x 10 “Something Big”

6 x 12 “Ocarina” | Jake character development

6 x 14 “Princess Day”

6 x 16 “Joshua and Margaret Investigate”

6 x 19 “Is That You?” | Flame Princess arc

6 x 22 “The Cooler” | Flame Princess arc

6 x 23 “The Pajama War”

6 x 24 “Evergreen”

6 x 25 “Astral Plane” | Martin arc

6 x 26 “Gold Stars” | Lich arc

6 x 27 “The Visitor” | Martin arc

6 x 28 “The Mountain” | Flame Princess arc + Lemongrab characterization

6 x 29 “Dark Purple” | Susan Strong arc

6 x 32 “Friends Forever” | Ice King characterization

6 x 35  “Graybles 1000+” | Foreshadowing

6 x 38 “You Forgot Your Floaties”

6 x 39 “Be Sweet” | Lich arc + LSP character development

6 x 40 “Orgalorg”

6 x 42 “Hot Diggity Doom”

6 x 43 “The Comet”

Season 7

7 x 1 “Bonnie & Neddy”

7 x 2 “Varmits”

7 x 4 “Mama Said” | Finn/Jake character development

7 x 5 “Football” | Adorable BMO (*)

7 x 6 “Marceline the Vampire Queen”

7 x 7 “Everything Stays”

7 x 8 “Vamps About”

7 x 9 “The Empress Eyes”

7 x 10 “May I Come In?”

7 x 11 “Take Her Back”

7 x 12 “Checkmate”

7 x 13 “The Dark Cloud”

7 x 14 “The More You Moe, The Moe You Know (Part I)” | BMO arc

7 x 15 “The More you Moe, The Moe You Know (Part II)” | BMO arc

7 x 18 “President Porpoise is Missing!” | Adorable + Marcy cameo

7 x 21 “King’s Ransom”

7 x 25 “Flute Spell” | Introduces Huntress Wizard

7 x 26 “The Thin Yellow Line”

7 x 27 “Broke His Crown”

7 x 28 “Don’t Look”

7 x 29 “Beyond the Grotto” | Established more AT universe/cool (*)

7 x 30 “Lady Rainacorn of the Crystal Dimension” | LR backstory (*)

7 x 31 “I am a Sword”

7 x 33 “Normal Man”

7 x 34 “Elemental”

7 x 35 “Five Short Tables” | Gender bending (*)

7 x 36 “The Music Hole”

7 x 38 “Preboot”

7 x 39 “Reboot”

Season 8 

8 x 1 “Two Swords” 

8 x 2 “Do No Harm” | Finn / Fern characterization

8 x 3 “Wheels” | Jake characterization/background (*)

8 x 4 “High Strangeness”

8 x 6 “Jelly Beans Have Powers”

8 x 7 “The Invitation”

8 x 8 “Whipple the Happy Dragon” | Susan Strong arc + Finn characterization

8 x 9 “Mysterious Island” | Finn characterization 

8 x 10 “Imaginary Resources” | BMO characterization 

8 x 11 “Hide and Seek”

8 x 12 “Min and Marty”

8 x 13 “Helpers”

8 x 14 “The Light Cloud”

8 x 16 “Skyhooks”

8 x 17 "Bespoken For”

8 x 18 “Winter Light”

8 x 19 “Cloudy” | Finn character development 

8 x 20 “Slime Central”

8 x 21 “Happy Warrior”

8 x 22 “Hero Heart”

8 x 23 “Skyhooks II”

8 x 24 “Abstract” | Jake arc 

8 x 25 “Ketchup” 

8 x 26 “Fionna and Cake and Fionna” (*) 

8 x 27 “Whispers” | Lich/Sweet P arc + Fern characterization

8 x 28 “Three Buckets”

Season 9 

9 x 1 The Wild Hunt

9 x 3 “Son of a Rap Bear” | Flame Princess arc

9 x 4 “Bonnibel Bubblegum”

9 x 5 “Seventeen”

9 x 7 “Marcy and Hunson”

9 x 8 “The First Investigation” 

9 x 10 “Jake the Starchild”

9 x 11 “Temple of Mars”

9 x 12 “Gumbaldia”

Pizza Mozarella and large fries~

Here’s a better chart so far, I’m posting here for anyone trying to breed. credit to the people who compiled the data on reddit