This is just a list that I've compiled over time. I'm sure theres stuff I have left out so if you can think of anything else please tell me. Thanks, hope this helps!!
*(You can also print this and check off what you have and don't have)*
What to bring
[] Marker (optional: spare marker)
[] Mask
[] Co2/HPA
[] Barrel Plug and Barrel Sock
[] Hopper
[] Waiver Forms (You must have them signed in order to play!)
[] Insect Repellent
[] Sun Block
[] Water (do NOT bring beer, pop, etc.)
[] First Aid (Band Aids, ACE wraps, disinfecting spray, aspirin, etc.)
[] Spare socks and shoes (bring many pairs of socks)
[] Spare clothes (bring quite a few changes of clothes)
[] Toothbrush and toothpaste
[] Deodorant
[] Toilet Paper
[] Tent/Camping Equipment
[] Sleeping bag and pillow
[] Lanterns (Battery kind, not flame. You dont want a tent fire!)
[] Firewood (Only if their campsite allows fires)
[] Ghillie Suit
[] Raingear
[] Spare gun parts
[] Flashlight
[] Towels and rags
[] Allen wrenches
[] Digital Watch (Set it to the game clock)
[] Squeegee
[] Radio w/ headset
[] Table
[] Camera
[] Tarp
[] Duct tape
[] Wet wipes
[] Batteries
[] Food (Beef jerkey is always good)
[] Cleats
[] Ear plugs
[] Smoke bombs
[] Binoculars
[] Fishing line (For trip mines. It must be breakable and CANNOT trip people!)
[] Megaphone (For team management)
[] Cell-phone *Dont take it onto the playing field. It will get smashed...

*
[] Tactics and plans
[] Maps (You can usually get a field map off their site)
[] GPS (For all you extreme players out there.)
[] Night Vision (Again, for all you extreme players out there.)
[] Goldbond Foot Powder
[] Camelback Water
[] Any extra weapons (Mortar, bazooka, mines, etc.) (Have them approved by the field management!!)
[] EXTRA MONEY!! (More than likely you will end up needing more money than expected for paint, gas, food, etc.)