How do I fence someone way taller with a huge reach? I can't get close without getting hit.
Stop trying to out-reach them and make distance your weapon: stay just outside their lunge, make them commit first, then close fast and fence where their long arms become a problem. Height helps most at long range and against newer fencers. Up close, and in sudden changes of direction, a shorter fencer usually has the edge, and tall fencers themselves will tell you that opponents who get inside and stay there give them the most trouble. Your blades are the same length; the difference is arm and lunge, and good footwork shrinks it.
A tall fencer wants you walking steadily into their extended arm, so never give them a predictable rhythm. Use small steps, half steps and sudden accelerations. Bait them: step in to draw an extension or lunge, break distance so it falls short, then take the blade with a parry or beat and go while they recover. Work them toward the end of the strip before you commit, because with little room behind them their retreat and stop-hit game gets much harder. In foil and sabre, if they hold their point in line, right-of-way requires you to deflect the blade first, so a firm beat or bind comes before the charge.
Adjust by weapon. In épée their reach means they get to your body first, so hunt the targets closer to you: wrist, top of the hand, forearm, and the front knee or foot when they extend. When you do close, keep their blade engaged with a bind or opposition and finish forward rather than recovering back into their range. In foil, right-of-way helps you: take the blade and attack, and remember that fencing at close quarters is legal as long as both of you can wield your weapons. Many tall foilists struggle to find an angle up close. In sabre their extended arm is valid target, so draw the attack short and cut the arm, or parry and riposte.
Be patient. After losing a touch, the urge is to rush in, which is exactly what a long stop-hit feeds on. Take your time, reset your distance and make them work. Off the strip, train acceleration with short sprints and explosive footwork, and play distance games with a taller clubmate, such as one fencer advancing while the other tries to lunge on the perfect moment. Ask your coach for lessons on closing and taking the blade. Over time, as your distance sense grows, reach matters less and less.