What are Key Quests?
Key quests are the quests that have to be finished to get your Urgent quest and unlock higher levels. This holds true for both Online and Offline. Below I've compiled a list of just the Key Quests from
http://monsterhunter.wikia.com/wiki/MH3U:_Guild_Quests Its better formatted on my PC where its outlined format but still handy to have.
HR 1 (Low Rank)
1. Playing With Fire
a.
Deserted Island (Day)b. Qurupeco
i. Can Call a Rathian
2. Leading the Charge
a.
Sandy Plains (Day)b. Barroth
3. The Merchant’s Mission
a.
Flooded Forest (Night)b. Rathian
4. Accident Investigation
a.
Flooded Forest (Day)b. Gobul
5. Urgent! The Fisherman’s Fiend
a.
Deserted Island (Day)b. Lagiacrus
HR 2
1. The Horned Wyvern
a.
Sandy Plains (Night)i. Bring Hot Drinks
b. Diablos
2. The Desert Gourmand
a.
Sandy Plains (Day)i. Bring Cool Drinks
b. Nibelsnarf
3. The Creeping Venom
a.
Tundra (Day)i. Bring Hot Drinks
b. Gigginox
4. Denizen of the Molten Deep
a.
Volcano (Night)i. Bring Cool Drinks
b. Agnaktor
5. Urgent! Double Trouble
a.
Deserted Islandb. Monsters
i. Rathalos
ii. Rathian
HR 3 (High Rank)
Just some quick notes on High Rank and beyond. You no longer always start at base camp. Also supplies are dropped at random times. More than likely you'll be seperated from your team with no map, unless you have the armor skill for that. There is a Feline skill to make Supplies drop at the beginning as well. The big take away from this is that any supplies you need you should remember to bring on your own.
1. Splash Damage
a.
Deserted Islandb. Monsters
i. Plesioth
ii. Unstable possible other Monsters
2. Mud Brothers
a.
Sandy Plainsb. Monster s
i. Barroth x 2
ii. Unstable possible other Monsters
3. Bye-Bye, Bloom
a.
Flooded Forest (Day)b. Monsters
i. Crimson Qurupeco
1. Possible Called
a. Deviljho
i. Honestly haven’t done one w/ out Jho showing
b. Pink Rathian
4. Supply Constraints
a.
Flooded Forest (Night)b. Great Wroggi x 2
5. Urgent! Brachydios Mio!
a.
Volcano (Night)i. Bring Cool Drinks
b. Brachydios
HR 4
1. Unwanted Visitor
a.
Deserted Island (Day)b. Monsters
i. Zinogre
ii. Unstable Possible Other Monsters
1. Arzuros
2. Tumble on the Tundra
a.
Tundra (Day)i. Bring Hot Drinks
b. Monsters
i. Baleful Gigginox
ii. Jade Barroth
iii. Unstable possible other Monsters
3. Heroes Wanted
a.
Volcano (Night)i. Bring Cool Drinks
b. Monsters
i. Uragaan
ii. Unstable possible other Monsters
4. Urgent! Ruler of Two Realms
a.
Deserted Island (Day)b. Ivory Lagiacrus
HR 5
1. Desert Desertion
a.
Sandy Plains (Night)i. Bring Hot Drinks
b. Monsters
i. Sand Barioth
ii. Black Diablos
2. Echo Location
a.
Tundra (Day)i. Bring Hot Drinks
b. Monsters
i. Glacial Agnaktor
ii. Unstable possible other Monsters
3. Bedevil a Deviljho
a.
Tundra (Nigh)i. Bring Hot Drinks
b. Monsters
i. Deviljho
ii. Unstable possible other Monsters
4. Azure Attack
a. Misty Peaks (Night)
b. Monsters
i. Azure Rathalos
ii. Unstable possible other Monsters
5. Throne of the Abyss
a. Underwater Ruin
b. Goldbeard Ceadeus
HR 6 (G Rank)
1. The Cherry Blossom Queen
a.
Deserted Island (Night)b. Monsters
i. Pink Rathian
ii. Unstable possible other Monsters
2. The Green Flash
a.
Deserted Island (Day)b. Monsters
i. Green Plesioth
ii. Unstable possible other Monsters
3. Avenge the Fallen Hunter
a.
Sandy Plains (Night)b. Monsters
i. Barroth
ii. Unstable possible other Monsters
4. Playing with Fire
a.
Sandy Plains (Night)i. Bring Hot Drink
b. Monsters
i. Qurupeco
1. Calls possibly
a. Rathian
ii. Unstable Possible other Monsters
5. Sweltering Showdown
a.
Sandy Plains (Day)i. Bring Cool Drinks
b. Monsters
i. Volvidon x2
ii. Great Jaggi x2
6. The Desert Gourmand
a.
Sandy Plains Night
i. Bring Hot Drinks
b. Monsters
i. Nibelsnarf
ii. Unstable Possible other Monsters
7. Axe to Grind
a.
Sandy Plains (Day)i. Bring cool Drinks
b. Monsters
i. Rust Duramboros
ii. Unstable possible other Monsters
8. Snowball Fight
a.
Tundra (Day)i. Bring Hot Drinks
b. Monsters
i. Jade Barroth
ii. Unstable possible other Monsters
9. Thunder on the Tundra
a.
Tundra (Nigh)i. Bring Hot Drinks
b. Monsters
i. Barioth
ii. Baleful Gigginox
iii. Unstable possibly other Monsters
10. Urgent! Sticky Situation
a.
Tundra (Day)i. Bring Hot Drinks
b. Brachydios x2
HR 7
1. Into the Danger Zone
a.
Sandy Plains (Day)i. Bring Cool Drinks
b. Monsters
i. Diablos
ii. Unstable possible other Monsters
2. Sand Barioth (Quest name not given yet)
a.
Sandy Plains (Day)i. Bring Cool Drinks
b. Monsters
i. Sand Barioth
ii. Unstable possible other Monsters
3. Deep-six a Deviljho
a.
Sandy Plains (Day)b. Deviljho
4. Green Nargacuga (Quest Name not known)
a.
Flooded Forest (Night)b. Monsters
i. Green Nargacuga
ii. Unstable possibly other Monsters
5. Ivory Lagiacrus and Gobul
a.
Flooded Forest (Night)b. Monsters
i. Ivory Lagiacrus
ii. Gobul
iii. Unstable possibly other Monsters
6. Stygian Zinogre
a.
Tundra (Nigh)i. Bring Hot Drinks
b. Stygian Zinogre
7. Rathalos and Steel Uragaan (Quest Name not Known)
a.
Volcano (Day)i. Bring Cool Drinks
b. Monsters
i. Rathalos
ii. Steel Uragaan
iii. Unstable possibly other Monsters
8. Agnaktor (Name of Quest not known)
a.
Volcano (Day)i. Bring Cool Drink
b. Monsters
i. Agnaktor
ii. Unstable possibly other Monsters
9. Urgent! (2 Great Baggi and 1 Brachydios (I think))
a.
Tundra (Day)i. Bring Hot Drink
b. Monsters
i. Great Baggi x2
ii. Brachydios
iii. Unstable possibly other Monsters
When you complete all these you have effective unlocked almost all the quests in the game.