An agent of any level can attach a Force Amp to an allied Portal at a cost of 800 XM.
Whenever an agent Hacks or Attacks an enemy Portal at close range, the Portal has a chance to counterattack. The "zap" drains the agent's XM reserves for an amount proportional to the Portal's level. The Force Amp multiplies this damage, increasing the XM and time required to neutralize the Portal.
Attaching multiple Force Amps to one Portal has diminishing benefits.
|1||Base x 2|
|2||Base x 2.5|
|3||Base x 2.75|
|4||Base x 3|
Properly deployed Force Amps will fully deplete an attacker's XM tank after each XMP barrage and disable his or her Scanner. While most agents carry hundreds of Power Cubes, continuously waiting for the "Scanner Disabled" animation to end, then using a Cube, then returning to the Fire XMP menu slows him or her considerably. This grants friendly agents leeway to recharge Resonators, wastes the attacker's game time, and makes the attack generally tedious and unsatisfying.
Because the counterattack's base damage scales with the Portal's level, Force Amps should be attached only to L 7 or L 8 Portals. Multiple Force Amps should never be deployed to the same Portal, as the effects diminish sharply. Instead, a single Force Amp attached to each Portal in a dense cluster will maximize the damage dealt per enemy attack.
Force Amps synergize well with Turrets and Portal Shields. The Force Amp multiplier is applied to each additional attack, exponentially increasing the damage output. In addition, Force Amps should always be deployed in conjunction with a Shield, since increasing the number of XMP's required to destroy the Portal also increases the total damage the Force Amp will deal over its lifetime.
A common modding pattern, FATTS, consists of a Force Amp, Turret, Turret, and Shield. When applied to a L 8 Portal, each portal zap will deal 10,000 XM of damage, with a 40% chance of dealing 20,000 XM. If an attacker is within range of three FATTS portals, each of his or her XMP barrages is almost guaranteed to fully deplete his or her XM tank. FATTS clusters are virtually impossible for a lower-level agent to engage and will put pressure on a high-level agent's resources and time.
Because Force Amps have zero stickiness, they will be rapidly destroyed. An agent should assume that each Force Amp in a Portal cluster will need replacement after a single skirmish.