Aikido techniques are usually a defence against an attack; therefore, to practice aikido with their partner, students must learn to deliver various types of attacks. Although attacks are not studied as thoroughly as in striking-based arts such as karate or taekwondo, “honest” or “sincere” attacks (a strong strike or an immobilizing grab) are needed to study the correct and effective application of technique. Many of the strikes (uchi) of aikido are often said to resemble cuts from a sword or other grasped object, which indicates its origins in techniques intended for armed combat. Other techniques, which appear to explicitly be punches (tsuki), are also practiced as thrusts with a knife or sword.
Beginners in particular often practice techniques from grabs, both because they are safer and because it is easier to feel the energy and lines of force of a hold than a strike. Some grabs are historically derived from being held while trying to draw a weapon; a technique could then be used to free oneself and immobilize or strike the attacker who is grabbing the defender.