Flak

Developed by the Terran Hegemony around 2310, Flak autocannon rounds are designed to be used in anti-aircraft units like the Rifleman or Partisan tank. This ammunition uses proximity charges to detonate in mid-air. While potent against fast-moving targets susceptible to foreign object damage (FOD), ﬂak ammo is less effective against slower-moving targets on the ground because the charges scatter their shrapnel too far and too quickly to beneﬁt from the target’s mobility.

However, the fragments generated by flak ammunition are too small to inflict significant damage on other combat units; it is partly the motion of the VTOL or fighter through the flak cloud that helps inflict the damage. The ineffectiveness against non-flying armored units is the reason why this type of ammunition is quite unpopular on today’s battlefield.

Game Rules
Flak ammo only inflicts half the normal damage on all targets except moving VTOLs and Fighters (AeroSpace and Conventional), WiGEs and conventional infantry. Used in attacks against moving VTOLs, Fighters and WiGEs, Flak ammunition confers a -2 to-hit modifier.