The term safety first is not just a motto. When we plan to use a particular simulation system, establish the parameters of use, and create a training environment to use that system the first thing we do is consider the safety of students, and bystanders.
If you don't know, airsoft uses replicas of real guns which fire very lightweight plastic pellets using compressed gas or electrically-driven pressurized air systems. There are also machine guns, hand grenades, rocket and grenade launchers, land mines, and more. Some of these use different but equally safe projectiles or means of propulsion. Critically, they are not legally firearms in any sense, anywhere in the US, and where we hold events so can be used without legal restriction.
While eye protection is absolutely required, at all times, the weapons employed cannot easily cause other types of injuries, are quiet so do not require hearing protection, and guns are quite inexpensive so most participants bring their own.
We employ airsoft due to the almost intrinsic safety, using it in environments where long range engagements are rare, and where close range fire could be dangerous when used with other systems. Firing actual pellets is useful as players will feel suppressed and will duck when they fly nearby.
Airsoft guns are ineffective at ranges over about 30 meters, so cannot be used in large open areas without excessive suspension of disbelief.
The guns are generally so quiet that it can be hard to tell a pitched battle is happening just 100 meters from you. This can cause problems with awareness and maneuver on the battlefield. Grenades (which do have a bursting charge so make more noise) and smoke are encouraged and often freely handed out as a way to offset this.
Ultimate Training Munitions fire pyrotechnically propelled projectiles through actual firearms, with conversion kits that make it physically impossible to fire live ammunition. Conversions are available for most self-loading rifles and pistols, allowing you to train with your actual weapon.
The weapon system works exactly as with live fire, but fires a very safe, low-richochet projectile, with no need for hearing protection. Target and force-on-force ammunition types are available.
The primary downsides of UTM are cost and availability. Ammunition is expensive, and not available for purchase by everyone. Conversion kits rival the costs of mid-grade airsoft guns, though much savings can be obtained by the use of actual weapons as no accessories light lights, lasers and optics need to be duplicated.
The use of actual firearms, and UTM cartridges not rated for force-on-force use, requires a vigorous safety system to assure that no one is shot. The use of actual firearms also means you can only have machine guns if licensed to, and cannot use grenades, grenade launchers, and other weapon systems at all. It would be possible to mix airsoft ancillary weapons with UTM rifles, however.
As with Airsoft or paintball, range is limited and there is little noise, so they are only useful at short ranges such as CQB or in dense woods.
The Multiple Integrated Laser Engagement System is a series of related simulation systems developed by the US Army for field exercises. It uses lasers attached to real weapons systems and sensor arrays on individuals or vehicles to sense hits.
When a blank is fired, the laser on the weapon fires. Near misses beep, and hits beep more, as well as shutting down the weapon associated with the hit participant, so they cannot continue shooting.
The lasers are mated to weapons and include details of their ballistics. Effective engagements have taken place with the actual systems we use at the fields we play on in excess of 400 m. CWG has a number of guns to rent, but you may bring your own as long as it meets the requirements and is legal, with all associated paperwork.
Since real guns are used, even with blanks, there is additional safety risk. Due to gas emitted from the muzzle, they cannot be used or safely for close range fights such as indoors simulations. Due to the narrow cone of the laser and a limited number of sensors on the target, they are also not very effective simulation systems at very close ranges.
As with UTM, since real weapons are used, you cannot easily have machine guns. CWG has access to only small arms emitters (SATs: Small Arms Transmitters), and individual harnesses (detectors), so cannot use rockets, or other systems. MILES grenades do not exist, and many other systems do not have simulators at all; it relies heavily on the use of observer-controllers with "God Guns" to simulate other systems instead.
Eye protection is required, but shooting glasses are enough for this; typical MILES events do not require more than this so cannot be inter-mixed with projectile firing such as UTM or airsoft support weapons and grenades. Hearing protection must be worn, and we will vigorously inspect all your equipment to make sure no live ammunition makes it onto the field. The blank attachments can absorb some fired rounds so there is a backup safety method to prevent anyone being injured.
Simulation doesn't always mean running around in the woods. It's very, very expensive to move a whole Brigade around, so many high level exercises are held with battle staffs only.
The staff sits in a room, looking at a computerized map and using radios or a computer messaging system to pass orders to lower level units. The enemy is in another room, performing their own missions, and for larger events the lower level units can be entirely other staffs accepting orders and acting up on them.
Administrators coordinate the action, determine based on algorithm what the results are of battles, weather, and terrain, and act as higher level command, attachments, the air force and lower level units not represented by players.
CWG has modified these systems to perform remote tabletop exercises reduced to the Company level, to extend our field scenarios up one tier of command, and allow the use of additional vehicles, long-range weapons such as artillery, and aircraft.