Awnings & Tarps
This is one of the single best investments a team can make. Keeping the sun and rain off of your head when you are not on the field can make things less fatiguing. We usually set up at least two 10 by 10 ft. awnings, sometimes more. I'd recommend about one awning of this size for every 4 or 5 people.
Three of the awnings we have are the quick set-up types in which the structure simply unfolds and pops up. They cost about $90 each, but to us are worth the price because of the quick set-up and take-down. Honestly, I did not know how long these EZ-up brand awnings would last when we first bought them, but we are starting our fourth season (at about a dozen events a year) with the two oldest ones and they have held up well - well enough that we recently bought the third indentical unit.
For cold, rainy or windy days, tarps can be used to wall in the sides of the awnings. We usually attach the tarps using plastic spring-loaded clamps which can be found along side tools in many department stores. The clamps are also great for many other uses such as hanging face mask from the awning frame.
It's also a good idea to bring along some extra tent/awning stakes and rope to replace those which get lost or damaged, or to help tie things down if necessary.

Tents and Sleeping Gear
One of the guys who plays with us likes to sleep outside regardless of the weather. That's fine for him, but if you are spending the night, having a tent to keep the rain, dew, bugs or frost off of your nose sure can be nice. Among the team we have a lot of different style tents, everything from the ten-man taj Mahal, to small tents barely big enough for one person. There are advantages and disadvantages which should be considered when buying a tent, such as cost sharing/saving, space availability at the camp site, or time consumption in set-up and take-down. Personally, I like the tent I use-- a 10 by 8 walk-in unit which includes built-in poles and stands up in about a minute. It cost about $60 at a department store, and from a convenience standpoint can't be beat.
Sleeping bags are a personal preference thing. I personally don't care for being inside one and usually just bring a blanket and sleep on top of the bag. However, for real luxury, one of the best investments I have ever made is an air mattress. For less than $20 you can sleep in real comfort, when compared to a sleeping bag on the hard uneven ground. And a good night's sleep can make a real difference in how you play paintball the next day.
If you have trouble sleeping amidst a lot of noise, ear plugs should be considered. From crickets, to generators running, to loud people who try to stay up all night long, a camp site at a scenario game can be noisy. Simple and cheap disposable ear plugs like those used for shooting can make a huge difference here.

Tables & Chairs
Having portable tables keeps from having to work off of the ground. Whether you are cooking, eating, working on equipment, writing, etc, it's much easier to do on a table, and you don't have to worry as much about losing things in the grass.
We have several different types of tables with folding legs. When buying these it's probably better to invest the extra money for something a little more sturdy. Cheap tables don't last as long and replacing them only cost extra in the long run.
Folding camp chairs can be found at most department or sporting goods stores for under $20. This is something each individual player can purchase for his or herself to help split the cost. It's much better than sitting on the ground.

Lights
If you're going to be staying overnight, it's a good idea to get some lights for the camp area. Some people prefer propane powered camp lights. Most of ours are battery powered, which seem to be easier to use when hanging them from the interior of the awnings. A few extra flashlights never hurt, in case some are lost. A small personal light can come in handy when going to the bathroom at night.
 
 
 
 
 

Water
We carry water in several forms. First and foremost is a 5 gallon jug full of ice water for drinking. The 5 gallon water coolers can be purchased from department and sporting good stores for about $25 each. It's usually best to fill them at least partially with ice. In order to avoid buying bags of ice, try freezing water in large plastic trays or tubs, creating big ice cubes. Sometimes, depending on the number of people, we bring 2 jugs, and sometimes fill one of them with Gatorade, but we always have at least one with water for drinking.
We also carry water in squirt and pump bottles. The small squirt bottles can often be found at discount stores for as little as a dollar. We will generally have one filled with soapy water and one filled with clean water. They're great for cleaning goggles and other equipment. Larger pump bottles can be purchased for a little more and provide some pressure behind the water for cleaning uses.
 

Paper Towels, etc.
Paper towels are pretty much an obvious necessity. The trick is to remember to bring them! Check out the paper towel rack on the Cheap Home-made Stuff page. It's also a good idea to bring a roll or two of toilet paper, since porta-potties at scenario games often run short. We usually carry some kind of liquid soap for washing hands.

Food & Drinks
At some point during the 24 hour game, it's likely you'll want to eat. While many fields sell food, it's often like concessions at a movie theater in that the cost is a little high. You can save a lot of money if the team pitches in and buys food together, not only for major meals, but for snacks and drinks.
Obviously some food requires the use of a cooler to stay good throughout a weekend, but there are also plenty of items you can buy which will last for weeks. We have a box full of snacks we keep on hand and replenish as necessary.

Cooking Equipment
A portable grill can certainly be considered a luxury item from one standpoint, but if you are looking to save money, it can be very cost effective. The grill we use is propane powered. We have used it to cook all types of food. Most of the time we eat both better and cheaper than if we had purchased food from the event, or went to a nearby restaurant.
Another handy item is a propane powered burner. This relatively low cost device can be used to quickly heat up a pot of food, or to boil water for coffee or hot chocolate when it's cold outside.
We also keep in stock paper/plastic cups, plastic utensils, paper plates, etc.

Tools & Parts
Murphy's law applies here. If something can go wrong with paintball equipment, it will. Developing a portable version of the same basic tools you use around the house to work on paintball equipment is a good idea. Keep in mind that you'll likely be at the field for more than 24 hours, and in some cases, the house may be hours away. Generally, what we carry is only limited by space, since we have learned from experience that the one tool you leave behind is the exact one you'll need the most. It might appear as if we take far too many tools to a scenario game, but inevitably, someone somewhere will end up needing a battery powered Dremel tool, drill, hacksaw, pipe cutter, or any other number of things beyond a normal tool kit. I even carry a soldering kit in case of emergencies with electric equipment.
We keep most of the tools in two large boxes designed to hold fishing tackle and tools. These boxes are compartmentalized with plastic trays and make it easy to keep a variety of spare parts such as o-rings, seals, screws, etc.
Having an empty plastic tray comes in handy when working on paintball guns or other equipment with small parts. You can drop screws, etc, in the tray instead of leaving them rolling around on the table where they can be easily knocked to the ground.
Don't forget you may also need tools to set up or take down camp, or repair other items beyond paintball equipment. Tools can also come in handy if your vehicle breaks down on a long trip. It happens.

Gun Rack and Ball Loader
These are luxury items, albeit cheap ones. The gun rack idea originated from not having a place to sit. It seems that after everyone came off the field during the game, they would lay their guns in the chairs and on the tables. The simple peg board gun rack solved that problem freeing up some much needed space. More details can be found on the Cheap Home-Made Stuff page.
The paintball loader is designed to help you load balls into the loaders you carry with speed and convenience. This can really accelerate your ability to get back out on the field, or give you more time to do other things, depending on how you look at it. There are companies that sell such devices, but ours is home made with the details of how it was done found here.

Fire Items
If you're playing in cooler temperatures, a roaring fire in the evening can be really nice. Before you plan on building a fire at the campsite, it's a good idea to check with the field owner/operator about local ordinances which may require a metal fire ring or other container, while prohibiting fires built directly on the ground.
Most scenario games are played in the woods and therefore a lack of firewood wouldn't appear to be a problem, but the field owner/operator may not want you dragging logs out of the woods to burn. It's possible you may need to bring your own firewood to the campsite.
A variety of camping related fire starting devices are available at department and sporting goods stored, and it's also a good idea to have a few tools such as an ax, a shovel, or other implements..  Always think safety first.
 

Generator
A portable generator really is a luxury item. Generally speaking, generators are expensive, but not at all uncommon at scenario game camp sites. We use a small gas powered Coleman unit, which puts out enough power to run a television set and DVD player so we can watch a movie the night before the game. The generator can also power a small microwave oven (great for breakfast), or a variety of power tools if necessary. In an emergency, it can even be used to jump-start a vehicle.
 

Spare Equipment
We bring lots of spares. From spare guns, face mask, ball haulers and clothes, to tools, tires, and even a spare tent most of the time, we almost always have an extra what-ever-it-might-be. Someone, somewhere will eventually need it – you can count on it.

Shower
A shower at the field is pure luxury. Like a lot of teams, we usually arrive for 24 hour scenario games on Friday afternoon, and spend both Friday and Saturday night at the field, not arriving back home until Sunday night. That's a long time for dust and dirt to collect on your body, not to mention who knows what else. The portable shower unit we have sets up in minutes and provides hot or cold water. Due to the number of people we usually have at an event,  a 55 gallon plastic drum is used to feed the shower. It's a great thing to have before the long ride home Sunday afternoon, as one of our players says "to wash off the first layer of dirt". If you get a shower, don't forget to bring a towel!
 

TV and DVD
Another pure Luxury is a TV and DVD player (which of course requires a source of power). We usually arive at the games Friday afternoon, so having the ability to watch a movie Friday night is nice. Generally Speaking, the bigger the crowd, the bigger the TV you need. Besides being harder to see, small TVs often can't put out enough volume. The one we use most often is a 19 inch model, which seems to work adequately. If you plan on doing something like this, you might try picking up a cheap TV at a pawn shop, so if anything happens to it you won't be out a lot of money.

Duct Tape
Can't forget the most important item on the list. Duct Tape is like the Force; it has a light side, a dark side, and it binds the universe together. Don't leave home without it.

RV (new addition)
Not too long after first writing this page we bought a motorhome . We had been tossing around the idea of this for a while, and after spending nearly a month of nights each year in a tent, it was finally time to try something different. Two of us on the team went in together and bought this 1991 model, 29 foot vechicle for under $10k, a reasonable price in my opinion. It will also be used by both of us for other non-paintball (family) trips, which helps justify the expense. Although gas milage is horrible compared to small vehicles, the cost is not so bad when you figure the thing can actually transport the amount of people that would have otherwise required three cars. There are some down sides to be considered, such as possible maintenance cost (afterall, the thing is a house on wheels), but the positives are really nice. The built-in bathroom, shower, generator, storage space, microwave, coffee maker, central heating, and sleeping space are all obvious luxuries when it comes to a paintball trip. The comfort level for travel and even just relaxing while at the field are miles above anything we have had before. And the whole thing even saves time in putting up and taking down camp, since so many items we previously carried separately are incoporated into the vehicle.
 

Billy Goodman