The half-thrust or the thrust on on the firm foot is the tactical secret of these texts. It can be at once a provocation, an invitation and a way of testing the opponent's reactions. Everything in LongEdge Fencing's practice is based on proper execution of the half-thrust.
To find out what your enemy wants to do, give him the advanced sword with the body bent forward and the dagger close to your sword. Draw near him to see if he wants to parry with his dagger or his sword.
— Cavalcabo
For my part, I would pretend to attack in order to induce the enemy to strike first, so that I should have the measure to thrust or offend his closest parts, with the intention of awaiting his riposte, preparing nevertheless the counter.
— Cavalcabo
Recollect this when you want to start your attack: you must carry a resolute point to the enemy's face, so that he is subjected [“obligated” may have been a better word choice here] to parry. If he does not parry, let the botte go to his face.
— Cavalcabo
In general terms, the half-thrust consists of four distinct actions which must be combined into one smooth movement sequence. It begins from and ends back in a solid guard stance.
This short video shows the basics of the Half-Thrust and a range of uses of the Half-Thrust in the attack. Additional pages and lessons assume the proper execution of the Half-Thrust.
Later texts (particularly Charles Besnard's Independent Master of Arms) describes the posture at the end of Step 2 such that a plumb line hanging vertically will touch the forward shoulder, the knee and the front of the toes of the forward foot. Do not go allow the knee or shoulder to go past this position.
Always remember to maintain your balance so that from the forward-weighted posture at the end of Step 2 you can easily move backwards, forwards, left and right.