An actuation system, characterized in that the actuation system comprising: a housing (302, 902) having a bore formed therein; an autolash piston slidably disposed within the bore in the housing (302, 902), the autolash piston including a proximal chamber (316, 916), a middle chamber (320, 920), and a distal chamber (322, 922); a main valve (338, 938) slidably disposed within the autolash piston, the main valve (338, 938) having a closed configuration in which the main valve (338, 938) substantially prevents fluid flow between the distal chamber (322, 922) and the middle chamber (320, 920), and an open configuration in which the distal chamber (322, 922) is in fluid communication with the middle chamber (320, 920) and a main accumulator (354, 954); a trigger valve (330, 930) configured to selectively place the proximal chamber (316, 916) in fluid communication with a trigger accumulator (332, 932); a lost-motion piston (364, 964) slidably disposed within the distal chamber (322, 922), the lost-motion piston (364, 964) being coupled to a component of a valve train (200, 400, 500, 600, 700); wherein when the trigger valve (330, 930) is opened, fluid flows out of the proximal chamber (316, 916) through the trigger valve (330, 930), the main valve (338, 938) moves to the open configuration, fluid flows out of the distal chamber (322, 922) into the main accumulator (354, 954), and the lost-motion piston (364, 964) moves proximally within the autolash piston, thereby allowing the valve train (200, 400, 500, 600, 700) component to be pushed away from one or more other valve train (200, 400, 500, 600, 700) components to allow an engine valve (206, 706) to close. a housing (302, 902) having a bore formed therein; an autolash piston slidably disposed within the bore in the housing (302, 902), the autolash piston including a proximal chamber (316, 916), a middle chamber (320, 920), and a distal chamber (322, 922); a main valve (338, 938) slidably disposed within the autolash piston, the main valve (338, 938) having a closed configuration in which the main valve (338, 938) substantially prevents fluid flow between the distal chamber (322, 922) and the middle chamber (320, 920), and an open configuration in which the distal chamber (322, 922) is in fluid communication with the middle chamber (320, 920) and a main accumulator (354, 954); a trigger valve (330, 930) configured to selectively place the proximal chamber (316, 916) in fluid communication with a trigger accumulator (332, 932); a lost-motion piston (364, 964) slidably disposed within the distal chamber (322, 922), the lost-motion piston (364, 964) being coupled to a component of a valve train (200, 400, 500, 600, 700); wherein when the trigger valve (330, 930) is opened, fluid flows out of the proximal chamber (316, 916) through the trigger valve (330, 930), the main valve (338, 938) moves to the open configuration, fluid flows out of the distal chamber (322, 922) into the main accumulator (354, 954), and the lost-motion piston (364, 964) moves proximally within the autolash piston, thereby allowing the valve train (200, 400, 500, 600, 700) component to be pushed away from one or more other valve train (200, 400, 500, 600, 700) components to allow an engine valve (206, 706) to close.