Type: Metapsionic
Source: Complete Psionic
You can manifest powers that knock creatures off their feet.
Benefit: To use this feat, you must expend your psionic focus. Knockdown Power knocks any creature caught in its area prone if the target fails its saving throw to avoid any or all of the damage of the power. It can only be applied to powers that allow Reflex saves and affect an area (a cone, line, burst, and so on). Powers that do not allow saving throws gain no advantage if they are made into knockdown powers. Creatures with evasion are knocked prone if they fail their Reflex saves (creatures with improved evasion are not knocked down if they fail their saves). Flying creatures affected by a knockdown power that fail their saving throws are forced down 10 feet.
For example, if a creature makes its saving throw against a knockdown energy cone but still takes half damage, it is not knocked prone. If it fails its save and takes full damage, it is knocked prone. Using this feat increases the power point cost by 2. The power's total power point cost cannot exceed your manifester level.