Just Cause 2

The completion percentage is easier to keep an eye on after you complete the story missions and start "mercenary mode". From what i have gathered this is how much each thing gets you and the order that they should be done to reach 75% the quickest:

Kill Colonel: 0.14%
Challenge: 0.10%
Faction Item: 0.03%
Complete Location to 100%: 0.03%
Resource item: 0.01% (sometimes less)
Sabotage: (destroy things like fuel tanks) >0.01%

By the time you are reading this solution you have surely come across the completion percentage score that will pop up every time you cause mayhem or complete something. This score needs to be raised to 75% in order to get the achievement.

To do so I recommend you play the story first. There is no need to concentrate on this achievement at the beginning. Once you have completed the story you should be in the 50% area. This of course depends on how many villages you have taken over and missions completed. You will gain a certain percentage for doing the following:

- completing locations (about 0,03%)
- causing chaos adds (about) 0,005% per destroyed item
- killing colonels (about 0,14%)
- finding faction collectibles (about 0,03%)
- completing challenges (about 0,1%)
- collecting resource crates (about 0,01%)

After completing the story you will automatically switch to Mercenary Mode where you can roam around Panau to get more completion score while keeping what you did in story mode. I recommend you concentrate on the following achievements first before going for the remaining percent.

A Trusted Ally in Just Cause 2
Up to the Challenge 2 in Just Cause 2
Trying Everything Once in Just Cause 2
Faction Benefactor in Just Cause 2
Leaving No Rock Unturned in Just Cause 2
Freeroamer 2 in Just Cause 2
Destroyer in Just Cause 2
Professional Hitman in Just Cause 2

While doing these I also recommend stopping now and then to do some unrelated tasks to mix things up! You should end up with a completion percentage around the 70% marker depending on how much exploring you did before. All that is left to do is clear bases and villages while rounding up collectibles. Try to focus on the big bases first. The big harbour in the middle of the inner sea hold a lot of destructible objects (and a challenge for which you pretty much have to take out the SAMs first). Airports are also a good choice as are big cities.

Here is an interactive map that might help you get to the locations of interest. Many thanks to ReptarOnIce3000 for providing the link!

Edit - 15 September '14: Updated map reference.
Edit - 3 February '17: Updated map reference as by comment.

This one is straightforward but very time consuming. I myself reached this after I hit the 56 hour mark. Yea I know.. it's insane.

Make sure you explore and complete locations as well keep doing your challenges, missions and collect those Drug/Skull/BlackBoxes and you should get this... after a long time.

The map will be split into 9 sections (Given that you do the 3x3 stronghold takeovers. 3 for each gang of course.) Once that is done, all the collectibles / challenges will be revealed and you can begin harvesting.

I'd recommend completing the 9 stronghold takeovers first, as collectibles can remain hidden in some areas, until you take over a neighboring stronghold. Something to do with overlapping / close borders or something like that! Be prepared, once you take over all the strongholds, your map will become very very VERY messy. Just stick to one county and clear everything up and move to the next. Soon you'll be able to follow your progress with your own eye.

Good luck!

I noticed no one has numbers on their final count, probably because by the time you grind to 75%, you're so ready to be done with this game, the last thing you want to do is write up stats. But I guess I'm the glutton for punishment. :P

Here's my stats when the achievement popped; for those of you thinking about taking this on. Note that I didn't spend hardly any time goofing off in the world, I was either working on chaos, or a mission of some sort. Very little time went into seeing what I could rig from one thing to another. Also note that this was done on hardcore. You'll probably have an easier time clearing military bases on a lower difficulty and going for the hardcore clear on another playthrough. I was at about 27 or 28% when I finished the story, and I just went immediately to the next story mission as soon as I had enough chaos. With all that said, here we go:

Game Time: 71 hours, 21 minutes
Total Chaos, 1,339,950
Total Earnings: 6,936,929
All agency missions, faction missions and stronghold takeovers done

Challenges completed: 60 (could never get the hang of the base jumping ones)

Locations discovered / completed: 343 / 233

Resources acquired: 1692 (622 weapon / 584 vehicle / 221 armor / 265 cash)

Faction items acq: 235 (63 bbs / 95 dds / 77 skulls)

3727 kills including all 50 colonels

1699 sabotages (590 fuel depots!)

That's all the stats that are relevant for the 75%. Note that I don't think actually completing a location gets you any extra %, so don't kill yourself looking for that last transistor or generator in a location when there are PLENTY of other locations to go through.

If anyone wants any other stats, please message me or leave a comment here, and as long as I have the game (I trade a lot), I'll load my save back up and get that info for you. Good luck to you if you go for this!

Edit: I no longer own this game, so recovering more stats is now impossible!

Okay, this one isn't really hard but VERY time consuming. Here is a list of things that count toward the 75%

1. Weapon/Vehicle Armor Parts
2. Challenges
3. Faction Missions/Takeovers
4. Agency Missions
5. 100% settlements/bases
6. Destroying ANYTHING with the Panau star on it (red line with white star)
7. Killing Colonels
8. Faction Items (blue dots on map)

Now that you know what you have to do, its just a matter of putting the time in to do it.

I just unlocked this achievement today. I wanted to shorten my "post game" time so I instead did everything except for faction missions, challenges, and then finally the story missions.

I read guides on here while playing this game so I learned from this site that Colonels give 0.14%. You can also learn this stuff in mercenary mode where your percentage is more detailed. Also for those who have my way of thinking and want to rack up a high percentage BEFORE doing faction missions/challenges/agency missions, you are shooting for about 55 percent with only 9 challenges complete, NO faction missions complete, and only 2 agency missions complete. If you have 55 percent and then you do 50 challenges(for the achievement), all 49 faction missions, and then complete the game, you will hit 75% as you beat the game or maybe a mission before you beat the game. I was around 52% with 9 challenges complete before I did all of the missions, challenges, and story and I came up just short.

I will also include the already known info about what gives you what percentage, but I will also list what story missions give you since I couldn't find that info.

Colonels: 0.14% -Definitely do this. Very easy 7% in total

Challenges: 0.9something%- Completing 10 and 50 gives you an achievement, so obviously do this. I recommend you use the cheap helicopter from the black market for most of them, even the boat and car challenges.

Destroying items (fuel depots, transmission towers, etc): 0.01% so for every 100 of these you destroy will get you 1%. Do not confuse these with exploding barrels that you may find. those give chaos, but they don't count. The things that contribute to completing a location are what count. You can also check the "sabotage" portion of your stats to see what will count.

Resource items: something less than 0.01%. For every 100+ of these you will add 1% to your percentage.

Faction Items: 0.03% Every 50 items you collect will give you a total of 1.5%. Getting the achievement for collecting 150 of these items will therefore rack up 4.5%. I collected only 204 of these.

100% a location: 0.02%. I've seen back and forth about whether this counts, but there is no other way to explain a resource item that completes a location giving you 0.03%. It counts.

Faction Missions: 0.2%. This means every 5 missions you will gain 1% and 9.8% in total. After you finish all of these missions, you have gained over 10% though because you are rewarded resource items after every mission.

Stronghold takeover: Over 1%. These missions might actually reward the most percentage. Do these as soon as possible.

Agency(story) missions: 1%. If you do what I did and finish everything else before starting the 3rd mission, you are guaranteed to finish the story mode at 75% if you are at 70% before finishing the story missions.

Gameplay tips: If I was in a village or near one and I wasn't in a chopper, I would complete the village. Get what you can from Panau City when you are there, but the area is so vast in terms of collectibles/destructibles, you shouldn't bother worrying yourself with it. Once I had completed enough locations/found enough collectibles to upgrade my weapons, I took a chopper and tore through every base, airport and harbor. I didn't grab the resource items, I just wrecked the area and moved on, hijacking new choppers as needed. This racked up my sabotage total fairly quickly. Most bases get to around 55% completion after demolishing everything you can from the air. after I had been through every location, I then started completing villages, some bases, almost all of the airports, and almost all of the harbors. To be safe, Leave the Oil rigs alone, because I've read there is a glitch with the "black gold" faction mission. Maybe it was patched, but just leave the rigs alone until you have done that mission.. By the way, i knew where every base was because I took a jet and flew low over to all undiscovered locations. I did the destroying first because when I went back to grab the resource items, I wanted the location to be complete after I was done. While going back for the resource items, also make sure to grab the faction items (at least 150 of them for the achievement). Like some others have said, if you can finish a location, do so, but if it's one generator you're looking for, just let it go.

Some people work quickly and this step can go "fast" or if you mess around like me, it can take days and days. I finished with over 2300 destroyed items so it can take a while; don't expect for the 75% to just fall into your lap.

As I mentioned before, if you are doing the side stuff BEFORE you beat the missions, then the number you're looking for is 55% to be absolutely safe. This number is before you do 49 faction missions(10%), 50 challenges(5%, but you can complete all 75 for the extra 2.5%), and the 5 missions to complete the game.

Easiest stuff for the 55%:

Kill all 50 colonels. This is a simple 7%
Gather at least 150 Faction items (4.5%). I actually gathered 200.
Complete the Stronghold takeovers. This unlocks the faction missions anyway and gives what seems like the most percentage.

After those, I recommend using choppers to decimate bases, airports, and harbors, and afterwards just keep collecting resource items and completing locations. Panau City(all 3 parts) is a place I only recommend completing if you want 100% completion. Otherwise, please avoid.

My stats at 75.1% completion:
Game time: 77:49
Total Chaos: 1,505,080
Agency Missions: 7
Faction Missions: 49
Stronghold Takeovers: 9
Challenges completed: 60
Locations completed: 174(didn't know they actually did count)
Resource items: 1535(Weapon:567, Vehicle: 545, Armor: 207, Cash: 216)
Faction items: 204(Black box: 61, Drug drops: 82, Skulls: 61)
Colonels killed: 50
Total sabotages completed: 2366(164 sams, 253 generators, 253 towers, and 855 Fuel depots)

Resource items + total sabotages complete: 3901 items.

This was a long winded guide, but hopefully someone is helped by this. If you have a more accurate percentage than mine or want to post a tip that you want me to add to my guide, feel free. I will give you credit of course. Good luck!

Easiest way to do this achievement is to fully upgrade the little red and black helicopter, despite not having missiles, it is very quick and has dual cannons. easily evades police, is cheap and small and easy to pilot, and can be placed anywhere in the world via shop.
but it doesn't have very good armor so make sure to dodge enemy heli fire,

Just fly from location to location, completing them as you find them in the chopper, and buy another if you need it, do not buy cars or planes, they are a waste of money.
The red speedboat that looks like a fork is fine, it is extremely fast.
For towns and cities collect all of the weapon, armor and car parts FIRST, that way you can blow up the destructibles and get in your heli and fly away, and the police won't be able to catch you.

As for the hostile locations such as military bases, the best option by far is to just blow up all of the sam sites first, then kill as many buildings as you can. You will die over and over, but it's not too hard.

The worst military bases are the ones with the shafts that you have to go down and punch in a code, you only have limited time to get out otherwise you die.

Other than that it's one of those things where you have to sit down and play for hours and hours and hours on end.