suru verb (special), transitive verb
devise a plan; work out a plot
Transitive suru verb used for deliberately planning or scheming something, often with a strategic or slightly formal tone.
敵を倒すための策を策する。
Devise a plan to defeat the enemy.
彼は会社を乗っ取る陰謀を策した。
He worked out a plot to take over the company.