It may seem obvious, but this guide is about achievements and achievements only.
I take it for granted, that, if you're going for 100%, you're familiar with the basic game concepts. Thus, I will not explain those in this guide. Just a few notes and one-liner at most.

That being said, take a look at this awesome guide by Minorou, which explains pretty much everything you would want to know:

• https://gtm.you1.cn/sharedfiles/filedetails/?id=1477331498

Since Iceborne straight up doubles the achievements, and most of you will already have unlocked most of the base game achievements, I decided NOT to add them to this guide. I wrote a new one exclusively for the DLC, instead.

• https://gtm.you1.cn/sharedfiles/filedetails/?id=1931750665

These are story-related and can’t be missed. Just progress through the "assignment" quests.

You can fire an SOS flare from your menu, if you're the one, who posted the quest.
Respond to an SOS flare can be found at any quest board after you've selected "join a quest".

You can cheese the 50 guild cards with a friend. Just accept, delete, repeat.
Should be easy to collect 50 different cards just by accepting every card coming your way, though. You can also send your card to the whole room, everytime you enter a new session. There's a good chance, judging by my own experience, that people will send their card to you in return.

Honestly, most of the stuff in this section is self-explanatory. I won't bother repeating what the game is already telling you. Just a few hints from my side.


Like I said, these are the ones, which the game explains itself.



Ignore this one. It will happen naturally, while you play through Iceborne.



These are NOT referring to the "Special Arena: [Monster]" quests.
The arena quests for this can be found in the Gathering Hub section of the town. Those quests, where you are given predetermined equipment. This also includes the "Challenges" available by the same NPC.
Note, that these quests will reward you with neither HR points, nor research for the monster you're slaying. But the kills will count towards the 500 hunted monsters.
And yes, it's valid to do the same quest 50 times.

Personally, I did the Kulu-Ya-Ku quest 50 times with the duals, because they come along with 2 flash pods and a shock trap. I used them back-to-back and the Kulu-Ya-Ku pretty much always died once the trap ended. Took me about 2min per quest.
Though I was told in the comments, that the Gajalaka challenge can reliably be finished even faster.



You'll unlock tempered monsters, after you've hunted the Pink Rathian and therefor unlock free access to the 5th map, Elder's Recess. Starting from there, you'll find blue footprints of non Elder Dragon monsters. Gather enough and you'll be rewarded with tempered investigations eventually.
Tempered monsters are basically identical to the normal versions, they only deal more damage and become immune to flash bombs (!) after a few successful flashes, varying for every monster.
Tempered monsters are those, which have a purple color around their icons, both in the quest window and lower left corner of your screen during hunts.

For a stand-alone guide on crowns, check:

• https://gtm.you1.cn/sharedfiles/filedetails/?id=2193582642

With the arrival of Iceborne, only half of all the monsters available in the game are required for the following achievements, which includes all of the monsters named in the table below.

I decided to order them by their availability in the five 7-star event quests with highly increased crown chances. These are:


*Tobi-Kadachi received an Iceborne-exclusive event quests with a guaranteed Miniature crown.
**Black Diablos received an Iceborne-exclusive event quests with the same kind of increased crown chance.


For the base game achievement, this only requires researching until all yellow stars filled.

Get yourself the "Scholar" skill on your armor, to speed this up.
Also note, that you do NOT need to kill or capture monsters, in order to increase research. Even gathering footprints is enough. So, if you really don't feel like killing a specific monster over and over - Kirin, for example - you can just walk around the map, look out for some footprints and then return from the quest via your menu. NOT abandon quest, but return from it.
If you plan on doing so, get yourself the "Scoutfly range up" skill on your armor, too.
Or, to be more precisely:




There are quests, which give you guaranteed crowns. These are:


3 further hints on this:

If you're in a multi monster quest, like the quests just above, you can return from the quest, once you've slain the gold crown monster. You do NOT need to finish the quest.
Be sure NOT to abandon the quest, though! That will lose you the crown. Choose the return option just beneath abandoning!

Investigations with better rewards also have higher chances on crown sized monsters.
Those with at least 1 gold and 1 silver reward can work some real wonders. They're still inferior to the quests at the top of this section, but I can highly recommend them for Black Diablos and all of the Elder Dragons!

Take Ghillie Mantle and Shock Traps with you. Use the mantle and walk directly up to the monster. While it can't see you, place a trap directly beneath it. Now the monster will move into a certain pose, which will always be the same. Look for a certain point on the body of the monster, which you can easily set in relation to a certain point on your own character/armor. The top of your head usually works best.
Now restart the quest a few times, until the point of measurement is considerably higher or lower than usual. Chances now are high, that you're facing a crown monster. Now slay it.
Gold crowned monsters are roughly 25% bigger or smaller than the usual ones.

For some super helpful screenshots of the exact measurements, check out these absolutely amazing videos by Gaming with Abyss:

You have to use the fishing rod for this one.



Get yourself a raw meat, for example by killing Aptonoth or Apceros, and use the Barbecue Spit. A mini-game starts. There will be a slim timeframe after the music stops, in which the meat has the correct color. Take it off the spit in that moment and the achievement unlocks.



Hit the monster, while you're in the air for a few times and a mini-game, if you want to call it so, starts. The game will explain you the rules. Just fill the bar successfully.



Go into your room, the one which is located under the stairs to the smithy, and talk to your Palico housekeeper. Select "move to a new room" and this achievement will be yours.
There are 3 rooms you can have, with the first one being available from the very beginning.
You'll unlock the other 2 rooms after the 2 Zorah Magdaros quests respectively.



Only rarity 8 counts, so the orange rarity stuff. Will most likely need elder dragon materials.
Kulve Taroth weapons don't count for this one.



There are 15 camps, distributed over the 5 main maps. 10 of those are valid for this achievement. These being all the camps, which spots you have to discover yourself on the map, which then need to be unlocked through the resource center. Just like the one in the Ancient Forest, where you discovered your first Kulu-Ya-Ku. Just walk around the maps and you'll find the others eventually.
Or just join another player, who already unlocked the "hidden" ones, and teleport to them through the map. Once you "bought" the fifth camp at the resource center, this achievement is yours.

4 camps in Ancient Forest and Wildspire Waste
2 camps in Coral Highlands and Rotten Vale
3 camps in Elder's Recess.

For a full video guide on this, watch the following video by the youtuber GaijinHunter:

These 2 achievements require to take a Palico with you.

The easy way to unlock "First Friends" is by getting a guild card from another player and then going solo on a quest. The Palico seen in said guild card will now spawn somewhere in the area. He's marked on your map with a Palico symbol and have a shiny green marker over his head. Walk up to him, let your own Palico talk to him a second and the achievement unlocks.

At the start of your game, your Palico will have the gadget "Vigorwasp spray", which let's him spawn the healing flies. Just take your Palico with you on quests (so, accompenied by 1 other player + his Palico at most) and it will level up. You can see the current level of the currently equipped gadget in the statistics at the end of each quest.
Once it reaches level 6, you gain a new icon in your itembar. You can use it to call for the specific effect of the gadget equipped. This speeds up the leveling process for the remaining levels.
Once it's 10, the achievement pops up.

If you want to unlock more gadgets and actual "Tailraiders" instead of other players Palicos, take a look at this awesome guide by Asperyules:

• https://gtm.you1.cn/sharedfiles/filedetails/?id=1475736970

Or take a look at this video by the youtuber GaijinHunter:

I'll obviously only cover those pets in this guide, which are required for an achievement.

If you want them all, take a look at this awesome guide by Jynn, which lists all of the pets in the game:

• https://gtm.you1.cn/sharedfiles/filedetails/?id=1483569942

Alright, now that that's out of the way, let me mention, that you need to be prepared to look up the spots of the following pets dozens of times, before actually getting them. Wouldn't be worth achievements, if they weren't really rare, would they?


You can find the wanted fish, called "Petricanth", at 2 locations:

Rotten Vale – area 15
Elder's Recess – area 8 (camp)

He'll most likely ignore the "fodder" bait. You need to find yourself a "Baitbug". One of those is also located in Rotten Vale sector 15, but you can find them on dozens locations on each map.

For additional help, watch this video by HarryNinetyFour:

The "Prism Hercudrome" you need for this, can be found at every map:

Ancient Forest – area 1
Wildspire Waste - area 10
Coral Highlands - area 11
Rotten Vale - area 11
Elder's Recess - area 3

Can only be found at dawn and dusk.
Unlike the birds of the below 2 achievements, the Prism Hercudrome won't flee. So this one is an easy catch.

For additional help, watch this video by HarryNinetyFour:

The small white bird you need for this, named "Downy Crake" can be located at several spots:

Ancient Forst – area 1 and 8, riding the back of Aptonoth
Wildspire Waste – area 1, 4 and 8, riding the back of Apceros
-> They are more likely to appear during the day on both maps.

Be aware, that they'll flee immediately, once you come "near" them. Meaning some 15 meters or so. Once they spotted you, they are only seconds away from disappearing. So be sure to use the Ghillie Mantle (item you'll unlock during the course of the story), when looking for them.

For additional help, watch this video by HarryNinetyFour:

Being almost identical to the achievement above, you need to find the "Bristly Crake" in one of the following 2 zones:

Rotten Vale – area 5 and 15, riding the back of the Mosswine
Elder's Recess – area 5 and 11, riding the back of Gastodon

Be aware, that it'll flee immediately, once you come "near" it. Meaning some 15 meters or so. Once it spotted you, it is only seconds away from disappearing. So be sure to use the Ghillie Mantle, when looking for it.

For additional help, watch this video by HarryNinetyFour:

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Credits:

Thanks to Agent Smith for pointing out another section in Rotten Vale, where the bristly crake can be found.

Thanks to sintiendomevivo for several information regarding the gold crowns.

Thanks to splehpnala for his information on the guaranteed gold crowns in the (USJ) Blazing Azure Stars quest.

Thanks to Gvi for his hint regarding the Kulve Taroth weapons in relation to 5 rare weapons achievement.

Thanks to Kryzz for confirming, that "Challenges" count towards the 50 successful arena quests.

Also, none of the videos linked in this guide are made by me. If they helped you, the original uploaders - GaijinHunter, HarryNinetyFour and Gaming with Abyss - sure would be happy about a bit of feedback on their respective videos.

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Since I've already referred to some guides on all camps, all palico gadgets and all pets, I may as well refer to the following guides, which will help you to truly 100% the game even beyond of what the achievements want you to do:

• https://gtm.you1.cn/sharedfiles/filedetails/?id=1472081706
  
• https://gtm.you1.cn/sharedfiles/filedetails/?id=1479646654
  
• https://gtm.you1.cn/sharedfiles/filedetails/?id=1472852281

Have fun playing Monster Hunter World!