What you need

Today I will be explaining what gear you will need to fight in a couple scenarios of airsoft.

Backyard/casual airsofting - This is a small match between you and up to 10 friends before it becomes a tournament. So for this you will need to NOTIFY NEIGHBORS this is critically important to prevent fatal incidents before law enforcement, their protocol is to shot first and ask questions later.
What you will need:

• Gun (duh)
• Eye protection MANDATORY
• Snacks (you will get hungry)
• Water bottle
• Lots of ammo

As an organizer (this may be at your house or you could be helping someone organize) You will need to make sure you establish a boundary to avoid ricochets from hitting a civilian, failure to do so could result in lawsuits. Make sure you have a safe/staging area to load ammo, relax, take a break. Some good rules that you should tell others are.

1. Guns must remain safe at all times!
2. Do NOT point a gun at ANYONE, doesn't matter if you think you've cleared it mistakes do happen. 
3. Goggles are MANDATORY and must be worn by anyone going near an active battlefield.

  
Airsoft Wars/Battles  - This is an organized event held at a field and is normally a fee to play.
A list of what you will need for a day of airsoft.
Basic Items

1. Cell phone (in case of emergency)
2. Money (Admission, buy or rent equipment, or food)
3. Entertainment (Ipod or book, in case of long waiting times)

Equipment

1. Camouflage - (A pattern that you favour, but I'd go with something that matches your surroundings)
2.  Head protection - (Helmet, mask, balaclava)
3. Boots - (Combat or hiking boots, for nasty surprises that you may encounter)
4. Tactical vest, Plate carrier
5. Airsoft Gun - Make sure your airsoft gun complies with all regulations the field may have.
6. Barrel Cover 
7. Backup Gun - In case your primary gun breaks or fails.
8. Spare battery - lots for primary gun, and one for each additional backup. 
9. Lots of hi-caps - Make sure you do not exceed the field's regulations, if they do have one.
10. Night Optic - Nigh time battles, iron sights are hard to see during night.
11. Team or a Sponsor Patch - An excellent time for advertising.
12. Gun Maintenance - in case something goes wrong, eg, needle nose pliers, Set of hex-keys. Silicon Oil
13. Pen or pencil
14. Ammo, different weights or types. You will need a crap load.
15. Map of field - It is much more use full than it seems
16. Overproduction, most fields require full-seal.
17. Snacks, minimum 2 canteens of water, a couple of energetic granola bars are good at keeping you ready and energized.

I hoped this helped you on questions you may have had. If you have any additional questions please feel free to post a comment or head on over to www.airsoftadvise.webs.com to contact me. My name is Bodhi and I hope you have a great day