The absolute minimum requirement for a chuck box, patrol box or grub box is that it store your camp kitchen. So it's a place to keep your many varied camp kitchen items. This saves you from scrounging around your home kitchen for place settings, cooking utensils, spices and such every time you want to go camping. In the strictest sense a cardboard box could, in effect, be a chuck box. (Many people do that.) Also, nowadays there are many large, varied and inexpensive plastic containers that can serve the same function and have the added features of seal, easy stacking and they are water proof.
However, if you go camping much at all, you soon learn that it's not enough just to have everything. You also need work surfaces for cooking cleaning and food preparation. Camping table space is at a premium when you are doing outdoor cooking! Thus a good chuck box will also setup to give you work surfaces and utility features for your camp kitchen. As a matter of example, take a quick moment and look at your home kitchen. You might first notice there are a lot of drawers and cupboards. That's because cooking requires a lot of stuff. Then you'll probably see there's a lot of counter space. That's because you need easy to clean places to work with all that stuff. Then you may see things like the sink, spice rack, cup hooks, paper towel holder an so forth. These utility features put things at your finger tips because, when cooking, you have a lot of things to do in an often very limited period of time. Food burns quick!
What all this really means is that once you have a well outfitted chuck box your once lengthy camping checklist turns into only a few items with the grub box being one of them, so the 'getting ready to go' camping hassle is gone forever. And you won't forget any key items anymore because things are always there in your grub box just waiting for you. Once in the field you find the work surfaces and utility features are an absolute delight. So the real bottom line is you go camping more often!
Also, IT MUST BE PORTABLE! In fact, one person should be able to transport it, in it's fully loaded state, without strain. This is the mistake almost all chuck box builders and even most wood chuck box manufactures make. They use materials like 1/2" plywood which can weight around 50 lbs a sheet. Honestly, even 1/4 baltic birch is too heavy as it weighs 28 lbs a sheet. The heaviest product we manufacture weighs 25 lbs total in it's empty state. That should be your weight rule because you know it can be done.
Additionally, vibration from roadways ( especially washboard dirt roads ) tends to loosen the mounting screws used for hinges and other metal hardware. This can happen very quickly. Thus, chuck boxes that have been designed by 'real campers' ( those who camp more than, say, ten times per year ) tend to not use metal hardware at all.
Also, be careful of things that 'look' like they would be cool to have. For example, a lantern hung over the cooking and preparation area may 'look' like a good idea but those of us that really camp have learned this also attracts bugs. This, almost certainly, will lead to an unwanted crunch in your food. ;-)
Attachable legs are usually a very bad idea because they either require a great deal of effort ( time ) to attach or form a wobbly support system. A stand is a much more quick and stable means of achieving the right height. How quickly a chuck box sets up is a critical issue.
There are many other design and construction concerns that buyers should scrutinize and builders should consider. We have published a book that sums up the factors to be considered when building and even buying a chuck box. How to Design, Build and Outfit Your Own Camp Kitchen.
Remember also, your camping equipment should be at the center of your survival plan. Give me my camping gear and I can survive, with a large degree of comfort, almost anywhere, for an extended period of time.
Note: Chuck and grub are cowboy type terms for food. A chuck box, grub box, camp box, and patrol box are all the same thing.