Airsoft is played with a variety of Rules and Regulations around the world
Some Fields have their own Rules and standards. Everyone seems to have a different set of rules.
(Did you ever play cops and robbers or Cowboys and Indians. No two groups of kids play the same. It's alot like that.)
Level 1 or Beginner Level
Level 1 is the Beginners level, where guns are either Spring powered or Electric and the FPS is usually around 250 and / or about 0.5 Joule. The Target Market for these guns are young Kids who play with their friends in the neighborhoods, these guns are low-powered, Low Priced and have a low damage threshold. These guns would not be on par with most Airsoft fields' Skirmish play. Priced usually under $150.00 ~
Level 2 or (High end Beginner or Low end Competitor)
Level 2 is a Starter Competitive Gun, Good Stock parts with no upgrades, This is the Majority of guns you will see on the Skirmish fields. AEG, Gas or High-Power Spring(sniper). A beginner would do well with these guns and most are Upgradeable to Level 3 via different parts. FPS is usually higher and players use heavier BB's because the guns can handle the reduction in FPS with heavier BB weight. FPS is normally around 300 - 500 with .12g and or about 1 joule. Price ranging from $100.00 to $400.00 ~
Level 3 or Competition Level
Level 3 is the Competition Level where players have Modified their guns with stronger Springs, better gears, shims, bushings, motors, batteries, etc etc. These are considered High End and Only Serious Airsoft Players should Attempt these Guns. These guns will be High FPS and ROF, usually just at the Field Maximum limits. some even exceeding 2 joules, with some Sniper Rifles exceeding 5 joules ( these usually have a minimum engagement range i.e. 100' ). FPS is usually measured with Heavier BB's never below 0.20g , FPS can be as high as 400-425 using .25g BB's with AEG's and even Higher with Sniper Rifles. Prices after modifications range from $400.00 to over $2000.00 ~
Here is a Joule Chart using standard BB weights and Feet per Second
If you use Meters you will have to convert.....
BLEED / WELT at 15 Feet or closer, BLEED / WELT at 25 feet or closer, Bleed at 50 Feet or closer, All based on Joules, Newtons, 6mm, Starting FPS, and Normal Skin, There will be factors that could Impact the Measurements like Wind, Clothing, Thick Skin, Movement of Target, etc. etc. These Break Skin Numbers are only approximations.