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Packs Options and Sustenance - Operating from a Three Day Pack

Updated: Sep 19, 2023

"What do I put in my three day assault pack" is a common question. In fact, chances are you're on this site because you asked it. While there are endless blogs and videos showing you what to buy and how to load it, our participants find that its more of a cerebral exercise. When you decide to finally slim down your kit, ditch the 100L weekend pack, and get serious about doing more with less, no one single person is going to give you the right packing list.

Instead, our goal here is to help you understand the categories of equipment you'll need, what options are available, and what you should consider when selecting your kit. What food to carry, what shelter to use, and where to sleep are just some of the questions that may have new answers in a 3 day assault pack world. In addition to giving you a wide menu of options to choose from, we tapped some of our regular participants to see what they've selected and the reasons they did.

Men in multicam with weapons and packs walking in a snowy forest


This article is written for individuals about to embark on a military simulation or outdoor event that lasts 24 to 72 hours, and makes it some assumptions about your goals. Mainly:

  1. There may be no fixed based of operations for you to return to in that time

  2. You want to remain highly mobile and self sufficient

  3. You will include items like personal hygiene kit as part of your 'mission gear', and that you will be carrying other items in your pockets or on your belt.

If you already operate out of a Three Day Pack, then this article should provide you some insight into how others are selecting equipment and organizing their gear; information that is always helpful when fine tuning your own equipment. If you are new to the three day pack concept, then welcome to the club. There’s a lot to think about.


Part 1 - Pack and Sustenance

  • Pack Selection

  • Food and Water

  • Shelter Considerations and Options

Part 3 (Coming Soon)

  • Sleeping Equipment

Part 4 (Coming Soon)

  • Clothing

Part 5 (Coming Soon)

  • Support

  • Mission Equipment



Your pack is one of the most important items you will select and it is not an easy decision. The market is filled with new and used packs from military surplus or commercial companies. It's likely that your first pack won't perfectly fit your needs, and with experience you'll identify new features or functions that you'll look for in your next purchase. However, paying attention to the considerations below should help you get closer to what you're looking for at the beginning.

Mystery Ranch Overload and Fighting Equipment
Mystery Ranch Overload with Daypack Lid and Fighting Equipment (credit: Instagram

Pack Considerations


This is the internal capacity of your pack in liters or cubic inches. Typically, three day packs are marketed in the 30-50 liter (1830-3050 ci) size. You'll want something that can effectively hold all the equipment you'll be carrying. This will include your food, shelter, sleeping, and clothing equipment. It also has to carry any of the equipment you'll need to sustain your operations, and any mission equipment you're assigned by your team.

Two very important notes about capacity here. The first is that mission equipment can have a wide range of size requirements. If you're asked to carry a breaching kit and night vision, your extra space requirements are likely to be low. However if you're expected to take on a hide building operation, you may be asked to carry large and bulky items like camouflage nets and shovels. Focus on the types of roles you're most likely to do, and recognize that your choice of pack may not work well for both equipment requirements.

The second key note is that weather can dramatically impact your volume requirements. Operations in warm weather where you can sleep outside unaided may mean you need a bare minimum of packed sleeping/shelter gear. Operations in shoulder seasons or cold weather may require bulkier insulation and more robust shelter options packed inside your ruck. Once again, your pack choice may not work ideally for both options.

While it seems logical to choose a larger pack, note that a larger sized pack may not function well without a larger load. You may discover straps that can't cinch any tighter, or attachments that flop around. The extra volume also encourages over packing, which is it's own challenge. Conversely, select a pack that is too small and you may not have room for the mission essentials.

Empty Weight

This is the weight of your pack all by itself. If you're trying to keep your total load carried under 30% of your body weight, a heavier pack will eat up valuable mass that could be used for other equipment. Don't be surprised to find between 1.5 to 2.5 kgs (~3-5 lbs) taken up by your pack choice alone.

Load Transfer System

The design of a pack will always include shoulder straps, but it may also include a rigid frame and hip belt to help transfer the weight off your shoulders and onto your hips. If you're new to packs, this is a game changer for heavier loads. It's important to evaluate the padding on shoulder straps, and to determine if the mass you expect to carry would benefit from frames or belts. These features will make loads more comfortable to carry, but they can add weight or get in the way if you don't need them. Consider what mass you'll be carrying, and whether these features are important. Some packs feature belts that are removable or stow away when not in use. Others have removable frame systems for lighter loads.

External Features

PALS webbing is a common feature on modern military packs, but is absent on many commercial/civilian models or older surplus. The ability to attach external pouches can add modular capacity or easy access to key items, but it can also result in a pack becoming unbalanced or larger than originally planned. Other external features to look for include pockets for rifle butts or water bottles, and straps that can be used to attach larger items such as tarps or sleeping pads. These features are very useful, but do add weight and snag points if not managed well. It's worth noting that you'll want to find a pack in a colour way or camouflage that suits your needs.

Internal Features

Packs can contain internal organization pockets, as well as separators/attachment points for radios or water bladders. It's important to consider how much organization or separation you'll be likely to need. Do you need smaller pockets for batteries and electronics, or will you use your own packing bags within the pack? How will your water bladder be separated or hang within the pack, or is that not critical to you?

Design of Openings

The method by which you access items in your pack will be a set of features you deal with almost more than any other. A number of styles exist, including clam shell, trizip, and top loading. Some packs also include secondary access methods with front, size, or bottom zips. Take some time to visualize how you'll pack the items in your ruck, and how much work will be required to access them. Are you ok with pulling out most of your items to get to your sleeping equipment on the bottom? Or would you prefer the ability to access that directly? Smart packing can mitigate a lot of the challenges that come with single access point or top loading packs, but extra access points or packs that open fully may make the job easier. Other opening features you may want to look for include ports for routing antennas, cables, or hydration tubes out from the inside of the pack.

Arc'teryx Khyber 60 and Equipment
Arc'teryx Khyber 60 with contents and fighting equipment

Pack Options

There is no end to the packs available to you, however there are a few brands and styles that come up frequently. Mystery Ranch is a favourite for durability, comfort, and function. Eberlestock and Kifaru are another pair of commercial producers making solid packs. In the surplus realm, the USMC ILBE is popular, and some even continue to use the old ALICE packs for their removable frame and style.

List of packs being used by article contributors

  • Mystery Ranch 3DAP

  • Mystery Ranch SATL

  • Mystery Ranch Overload

  • Mystery Ranch Komodo Dragon

  • Mystery Ranch Pintler

  • High Ground Gear Three Day Pack

  • Arcteryx Khyber 60


Pack Recommendations


Tons of room for literally anything you could possibly bring. Lots of MOLLE real estate to attach extra pouches. Fairly adjustable for most frames and has a thick waist pad. The not so great: Weighs more than other bags, zipper system sometimes makes it a pain to get to things. Having used it for backpacking and bbwarz multiple times... I love it and don't really see myself replacing it anytime soon.

SA - Mystery Ranch SATL

I've used maybe eight or nine packs over the years. They all work well but I continue to refine what I'm looking for. Currently I'm using the Mystery Ranch SATL. It's a bit larger (60L) than a standard 3 day pack, and this can be a little unappealing in warm weather as it never gets filled full. However, I find that for cooler weather, it's capable of carrying my shelter, sleep gear, clothing, and food very well. It's tough to find a pack that works well for both winter and summer, but I'm hoping to apply packing discipline to ensure I can use just the one. A modification I made was to grab a Mystery Ranch day pack lid and used it instead of the stock lid on the pack. The day pack creates a quick and accessible go bag to use. I've also been experimenting with lashing my First Spear ECP to the front instead of using the day pack lid. Regarding access and organization, I really value the ability to access the contents of the pack without unloading it. The vertical front zip allows me to do that well. I've previously used an MR Pintler and I find the Trizip is comparable to the front zip for me. Internally, the pack has a pair of light nylon tube pockets running down the inside. I often use one for a UK Basha shelter, and load my cooking/filtration gear into the other. There are also a pair of 'torpedo' pockets on the front of the bag, which have a bit more capacity than the internal tubes. Externally, there are enough lashing points on the bottom and sides for extra netting/tarps if I'm building hides, and I often load my sleeping pad under the lid. Just the right amount of PALS webbing to attach a few accessories including my first aid kit and a small food pouch.

RS - Mystery Ranch 3DAP

For me the Mystery Ranch 3 Day Assault Pack comes at the end of a fairly long line of different packs. Some of the first packs I used were from offshore tactical companies like Condor or civilian companies like Osprey. While those packs served their purpose, they never served it well when it came to Milsim applications. In my search for the right pack I tried out packs from LBT, Tactical Tailor, Eberlestock and more. While they were certainly an improvement, none of them quite met my needs in a pack. Enter the Mystery Ranch 3DAP. Mystery Ranch builds their packs based on the combined knowledge from years of mountaineering and pack construction with direct input from tactical real world users. That means they aren’t cutting corners when it comes to features or materials in their product. The end result is something comfortable and highly functional. The primary features I was looking for in a pack were as follows: Scalable: As a tall guy, many ‘one size fits all’ packs were simply too small for me. I needed a pack with an adjustable yoke and a sized waist belt. Compressible: I wanted a pack could easily carry a full loadout, while not looking like a bag of dicks when only partially filled. This meant it needed compression straps to cinch down the load. Comfortable: Many packs I’d tried failed to strike the balance between padding, weight, and proper distribution of the load. Practical: Many packs I’d tried had features that simply weren’t needed, or poorly implemented. I wanted something simple and user friendly. Clocking in at just shy of 33L the 3DAP is one of the smaller packs I’ve used for 24-48 OPs. Surprisingly, I’ve never run out of room to the point something important was left behind. The downfall of many packs in this category in my opinion is too many compartments of 500-1000D cordura. These compartments are useful for organization, but are rarely filled all the way and they add a good deal of weight to the pack. This results in a heavier pack with wasted space inside it. All the compartments in the MR 3DAP are contained within the main body of the pack, and separated by mesh or light nylon. This means partially filled pockets don’t waste space. Additionally, the Tri Zip design allows for the pack to be loaded (and more importantly unloaded) in a very efficient manner. Finally the numerous compression straps allow many bulkier items to attach the the exterior of the pack, saving room inside for the essentials.

AS - Arc'teryx Khyber 60

I run the Arcteryx Khyber 50. Sometimes with the included lid and a MR daypack lid. It is too much for 24 hour operations, as a daypack would suffice but it fits the role quite well for 24+ up to 72 hours if I had it with all the bells and whistles. Here are my observations, in point form for brevity and clarity: 1. It is a top loader with no external pockets. This means that there are no water bottle holders, zippers or storage beyond the main compartment or lid. Extra care and thought in advance is required or else i may have to remove most items from my pack to get to the goodies at the bottom. 2. Being a top loader requires me to be disciplined in what I pack and and be mindful of what is packed at the top. In addition I would need to consider the basic rucksack packing principles of having heavy and awkward items higher and closer to the spine. One advantage is that because it is just one big bag, it is able to hold awkward sized items although it may be at the cost of being slightly imbalanced. I will mentally go through what I think will happen when we step off and what I will need first. If it is a dusk / evening step off, I usually would put an insulating layer or a shelter system near the top in anticipation of establishing a laying up area as a likely first major task. All the way at the bottom would be sleeping gear, change of clothes. Somewhere in the middle is usually food supply that is used strictly for resupplying smaller food items located on person or in the lids. Would also fit in the middle awkward items like canteen cups. closest to back outside of the liner would be my hydration bladder. 3. The pack is lined with a waterproof rucksack liner and individual compartments have their own ditty bags. 4. Because the bag is a top loader, I find myself needing to use all external storage options available to me. They include: -Two beaver tails. One at the lower 1/3 of the ruck and one above the main compartment that the lids rest on. These are designed for helmets and short antitank weapons think M72 LAW. The top one would be more secure for things like a LAW or maybe even another rifle. Disadvantage for the top one is that the lid needs to be flipped to access the beavertail. Advantage would be that it is more secure. The bottom one is better suited for a helmet. -Shock cord daisy chains running the length of the front of the pack. This is useful for sticking a basha or level 6 for easy access. It is fairly secure here and have had good success with it. -Daypack lid and included lid (sometimes one or sometimes two). Circumstances rarely warrant the use of both together but generally the day pack lid would have the bare essentials to sustain me: At least 1L of water, poop bags, TP and hand sanitizer spare magazines, sweater, NOD case, snacks, batteries, change of socks and fire kit. I am in the process of trying to up the 1L to two L using antibottles as I find 1L is too little for patrols. A challenge that I am facing here would be that my insistence on having my nod case and bringing an compression sack with sweater in the daypack leaves me with little room for additional water I want to carrry. I am considering removing the sweater in the day pack for all but the coldest events and bringing more water. -I added shock cord to the bottom of my ruck to attach a sleeping mat. It works well, is secure and can deploy and attach the mat very quickly. 5. Some advantages include that the pack is meant to be a mountaineering pack so the manner in which it synches allow for a lower profile in the unlikely event the ruck less than 50% loaded. The synch straps have also been used to carry hide building material but relies on the pack being almost full capacity out to secure properly. 6. Overall I think the type of pack has contributed positively a good kit management mindset in the field for me despite not being as easy access compared to tri zips. For example it forces me to think in advance and pack things away deliberately and I am usually packed and squared away very quickly. It forces me to be organized and in turn I am organized


Food is one of the items you will be required to carry over the course of your event, and your choices will have a serious impact on how you perform. Too little food brought may leave you tired and weak, while too much is mass that could be allocated in better ways. Your needs will also change with environmental and exertion factors.

The amount needed varies by person. In some cases, you may find that regular large meals keeps you at your best. In other cases, you may find that small snacks every hour or two works better. Determining your best operating state will help you select the types and amounts of food to bring. Experience is the best teacher here, so long hikes or overnight trips with various weather and exertion levels will help provide the knowledge you need. However, there are some operational considerations you may not have considered.

Will your unit be stopping for meal breaks, or will they be constantly on the move? Will the breaks be long enough to prepare a dehydrated meal, or will they only be five minutes at a time? Can you spare the water from your drinking supply to add to dehydrated food? Will your position be secure enough to use a stove with the associated noise and light, or will you be required to maintain disciplines that make this impossible? These factors must be assessed by you and your unit before you make a decision of what to carry.

Food for 24 hours outdoors in November
Selection of food carried by a participant for 24 hours of operations in November (credit: Instagram

Food Considerations


The more space and weight that your food occupies, the less room you have to haul other gear. The weight requirements of hydrated food can add up quickly, and should be factored into your pack weight. However, food is consumable. As you eat, you’ll gain that extra room in your ruck. Don’t forget that you’ll need to pack out all your trash. Keep this in mind if you’re considering food options with lots of packaging.

Personal Needs

Your experience will always dictate how much and what type of food you personally need to keep up your energy. Consider previous events you’ve attended and how you coped with the activity requirements and the food you ate. If in doubt, packing extra snacks and ready-to-eat (RTE) items is a small space investment but can pay off if you run low on meals.

Preparation Time

This is critical. Know that occasions to stop for 30 minutes and boil water to cook food might not happen regularly enough to sustain you. Also consider the possibility of being bumped during this stop. Will you be able to pack up your food and gear quickly and fight your way out or are you going to have to ditch it in place? What resources are you going to lose if you do so?

Preparation Needs

Do you need a stove? A pot? Do you need extra water? Have you factored these requirements into your load? A meal that requires extra equipment to prepare is less desirable than one you can simply consume. Do not underestimate how quickly these pieces of gear eat into your weight and space limits.


Water is critical, but there’s not much that can be done about carrying it. You either do, or you don’t. Your personal requirements will dictate how much you will need, but it could be in excess of 3L a day. You’ll have to consider the full spectrum of water needs, from drinking to cooking to hygiene.

Food Options

There are several types of food available to you for multi-day remote operations. Do not necessarily limit yourself to only one type. Consider mixing and matching in proportions that best fit your needs.

Snacks / Ready to Eat (RTE) / Prepared Food

These items may consist of energy gels and chews, energy bars, or simple trail mixes. They are very light and take up a small to moderate amount of space, but they require no preparation work or equipment and can be easily eaten on the move in short amounts of time. Additionally, some prepared items like sandwiches may work depending on weather conditions.

Shelf Stable Meat, Cheese, Crackers

Some Blackline event participants are are moving towards fresh food in the field. This means hard cheeses and shelf stable meat. Ensure you see the words ‘no refrigeration required’ on the package of meat before you take it into the field. These options allow you to eat high protein, high fat, calorie dense food quickly and easily.

Military Rations (MREs, IMPs, etc)

Military Rations such as the MRE or IMP box contain a meal consisting of multiple food items, accessories like salt and jam, and electrolyte drink mixes and/or coffee. MRE boxes are rather large and heavy, but can be broken down into their components so only necessary items can be packed. In the end, they’ll take up a moderate amount of space. Items are hydrated and ready to eat, and in most cases, heating is optional, giving you a chance to eat on the move. Boiling the package in water or using an MRE heater are both valid options but take additional time and resources.

Dehydrated Food

Backpackers pantry, mountain house, and other backpacking meals are one to two servings of food in a very lightweight package that takes up a moderate amount of space. These meals are dehydrated and require you to add boiling water and let the meal sit for up to 15 minutes before consuming. If this is an option you want to consider, you'll have to add a stove and fuel to your packing list.

Carrying vs. Treating Water in the Field

Water is a critical item. Aside from having enough to drink, some food options require the addition of water to rehydrate. The largest challenge with water is mass and volume. Every liter of water weighs one kilogram (~1 quart = ~61ci = ~2.2 lbs). In some cases, your operational environment will require you carry all your own water, and you'll have to factor this into your planning. Canteens and bladders are your two main options here, with bladders having the added benefit of collapsing down to save space when empty. If the option exists however, you can consider purification of water in the field.

Multiple methods exist for treatment, including filters, chemical additives, and simple boiling. Each of these can be very effective, but be sure to research the exact instructions and limitations of the various products before using them. As an example, some water filters will only remove bacteria, while others will also remove viruses. Also note that each choice comes with different equipment and time requirements. Filters take up more space than chemical tablets, and require time to do the filtering. However both can be faster than boiling which also requires consumption of fuel and creates light/noise.

Consider the seasonality of carrying vs. filtering water as well. Water sources available in the spring may be gone in the summer requiring you to travel further for resupply. In winter, you may be forced to boil for purification, and carrying water in sub zero temperatures may result in it freezing.

Finally, not all water sources are created equal, and the various treatments may not be able to remove chemicals or metals dissolved inside. Your choice to carry or filter may be made for you based on whether the water is flowing in a stream that travels through farmland or an urban center.

Food and Water Recommendations

S.A. - Snacks with Fresh and Dehydrated Food

Food preparation takes time. Boiling water or using heat packs means you're committed to your position. You risk having to lose/ditch all of that kit when you need to suddenly and urgently go mobile. I choose to use snacks and gels for most of my calories because they can be consumed on the move, and need no time to prepare. I used to choose MREs, but I've replaced them with dehydrated meals that I select specifically for quick rehydration times. I only really carry one though in case we have time to settle down. That said, do NOT underestimate the morale boosting power of a hot meal and some coffee. We typically ensure one man in the team is carrying a stove, and each member is encouraged to carry a metal canteen cup so that water can be boiled if the tactical situation permits.
For water, I’ve been moving to small bladders, with the addition of a water purifier. VAPUR makes some in decent colour ways and they’ve served me well on multi-day long distance hikes. They can be filled quickly, and they pack down to nothing when not in use. For filtration, I'm using an MSR Guardian which was designed for the military. It won't be damaged if temperatures drop below freezing, it's self cleaning, and fast. It removes both viruses and bacteria. All of that said, I have been burned by lack of water sources though, so validate they’re there shortly before your trip.

M.C. - Prepared / Fresh Food

In regards to food, one of the reasons why I keep breakfast sandwiches from McDonalds in my pocket is because they do last a long time, and they are a morale boost. Boiling water takes a long time, waiting for it to rehydrate takes time, plus you have to carry a stove pot and fuel with you. Why not bring sandwiches that have fillings that won’t wet out the bun and spoil it. Put it in some tin foil and then it’s ready to go immediately. I like a good high calorie trail mix, perhaps some fruit cups and of course energy food. Even pre-cooking bacon and throwing it in some ziplock bags is a great idea that requires no prep time. The waste from all of these things will cost you grams, not pounds, and it won’t take up much pack space.

A.G - Cheese, Meat

Some thoughts on food that are at the top of my mind from a recent event. To preface, I typically like to have most of my food ready-to-eat, with one hot-food option on standby in the event of extended rest time. The problem with hot food is that it requires a lot of space; a burner with fuel, and bulky freeze-dried packaging that typically don’t pack well. This weekend I opted to substitute my usual mountain house meal with some protein cookies. At 450 calories each I was able to store 3 of them in less or about the same space as a mountain house meal. For ~$3.60 each they were also notably cheaper per calorie than most of the mountain house meals which hover around $13. If you compare the cookies to cliff bars, they are about equivalent in terms of weight, calorie count and packability/size; 2 cliff bars = 1 cookie, although I have seen smaller cookies about the size of cliff bars if you prefer your food ~200 calories at a time. One thing I noticed in sub-zero temperatures is that the cookies didn’t get as hard as the cliff bars which effectively turn to bricks.

JBT - Cheese, Meat

I’m a big fan of cured meats and cheese, especially in colder weather. They also hold up well to getting wet, if everything goes that badly.

RM - Cheese, Meat

Best decision I made was making pre-packed salami havarti and prosciutto packs. Definitely jumping on this bandwagon as it was so nice to be able to eat while on the move

RS - RTE/Prepared Food

grabbing a few chicken nuggets. Warm them up and let them sit in room temp to cool down and place them in a ziploc bag. Eat them cold, fuck it, you're cold anyhow

JM - Cheese, Meat, Snacks

Various trail mixes are my current go-to for calories. You can get some that have some nice sweet bits added, M&Ms or better, plus nuts and other shit that adds plenty of calories. Not only that, you can share, too which is a bonus. Otherwise, meat and cheese are pretty great staples. Tastes good, lots of fat, and doesn't freeze too badly. Only issue with pepperettes is they tend to induce bad farts or early bowel movements.

BM - Cheese, Meat, Quick Prep Food

I tend towards the Old school.. meatsnacks - Schniders european style dry sausage, high fat, high protein and no refrigeration needed. For morning , instant oatmeal , Carbs, dry snakbread . I carry an ezbit stove. the fuel tabs are light and burn smokeless and will boil 500 ml of water in about 6 minutes. , nestle all in one for coffee , chocolate and hard candy to load calories when it's cold


In the next article, we focus shelter options and considerations.

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