Effective use of grenades
Units controlled by ArmA's artificial intelligence achieve remarkable accuracy with grenades. Is it possible as a human player to achieve such accuracy? This is a question many of the newer players to ArmA/OFP may ask.
The only way to get better at aiming grenades is to practice. Players familiar to the grenade physics of other popular games such as "Counter Strike" and the "BattleField" series may find ArmA quite different. Use the single player Training Mission to get used to aiming the grenades, or if you are based in an on-line squad, talk to your leader about different methods they may have devised themselves. The cadet mode crosshair can help you learn to aim grenades, but with time and practice it is possible to accurately predict the thrown distance without any crosshair.
Hand grenades can be thrown a maximum distance of ca. 70m. The minimum practical distance (without injuring the player himself) is about 30 meters. Due to the bouncing of the timed grenade it is very hard to accurately throw them at short distances though, as they may jump or roll another 50 meters or so after the ground contact.
The duration the trigger button is pressed when throwing a grenade has no influence on either the throwing distance or the detonation delay.
ArmA version 1.07 introduced secondary iron sights for under-barrel grenade launchers, allowing these weapons to be aimed much more precisely without any crosshair.
There are 4 types of grenades:
M67 (US) Grenade
Use a timer, exploding around 5 seconds after they are thrown. They can be successfully bounced off walls and other surfaces, but can give the enemy some time to evade the blast.
RGO (Russian) Grenade
Explode upon impact with a solid surface. These can be dangerous to use over short distances.
Emit white or coloured smoke used to provide concealment or to help identify a location, such as signaling a landing site to an incoming transport chopper.
Launched from either an under-barrel grenade launcher or from a mounted launcher. While they carry a smaller explosive charge than a hand grenade, they can be fired over much greater distance. Launched grenades explode upon impact, although they can deflect or "skip" along the ground if fired at a low angle.
Some successful tactics, often used by the AI:
Positionally Inaccurate Attack
Grenades can be very useful when only the approximate position of an enemy unit is known. The blast radius makes up for any error when targeting. Be careful, reckless use of grenades can easily lead to friendly fire deaths.
Grenades can be thrown or launched over obstructions that prevent direct rifle fire, such as fences or buildings. This makes them well suited to clearing fortified positions and urban combat.
Closely Grouped Enemy Soldiers
A single well aimed grenade can kill many soldiers in an instant. This tactic is very successful when used in ambush situations when the enemy are not aware of the thrower's presence. This is also a good reason to try to keep a safe formation spacing.