Miss your target reps three sessions running at the same weight and the answer is to take weight off: two grid steps down, then climb back through. Not one step, not a new program, and not more sets. The wall is information, and the response to it is boring on purpose.
One miss is noise
Any single session can go wrong for reasons that have nothing to do with your training. You slept badly, ate late, argued with someone, trained at 6am instead of 6pm. A rep count is a measurement taken through all of that.
So one miss means nothing and you repeat the weight. Two misses is starting to look like a pattern. Three consecutive sessions at the same weight without hitting your target is no longer a story about sleep. It is the weight.
Three is not a magic number. It is the smallest number that is distinguishable from bad luck, and waiting for four just costs you another wasted session.
Why two steps down and not one
This is the part people argue with, and the reasoning is simple: one step down is inside the noise.
Drop 5 lb from a weight you have failed three times and you are at a load you could probably also fail on a bad day. You will grind it, scrape past it, arrive back at the wall in two sessions, and have learned nothing. Two steps buys a genuine run-up: a weight you will definitely own, then a rebuild through the sticking point with momentum behind you.
The second climb is also not a repeat of the first. You are rebuilding through weights your body has already handled, which usually goes faster than it did originally, and you arrive at the wall having just completed several successful sessions instead of several failed ones.
What a real stall looks like
My EZ-bar curl has sat at 110 lb since mid-June. The rep counts across those sessions went 8, then 9 and 10 on a long day, then 10, then 10, then back to 8, 8, and 9.
Read the shape rather than any single number. It climbed, topped out, and then started sliding backwards at a fixed weight. That is a stall with a clear signature, and no amount of trying harder on the next Tuesday changes it. The weight has to come down before it can go back up.
Notice also what a stall is not: my weighted dips ran 60 lb for ten reps across five straight sessions in June and early July without wavering. Same weight for weeks is not a stall if you are hitting your target every time. That is a plateau in the weight column only, and if the reps are clean the honest read is that the target is what needs to move.
Things that are not the answer
A new program. Program-hopping at the first stall means you never find out whether anything works. The stall is not evidence the program is wrong; it is evidence that this weight is currently past you.
More sets. Adding volume to a lift you are already failing adds fatigue to a fatigue problem.
Grinding it out. A fourth and fifth attempt at the same weight is just three failures with extra steps.
Treating it as a personal failing. Every lifter who has trained long enough has reset a lift. The ones who keep progressing are the ones who reset early and without drama.
Reset, then forget about it
Take the two steps off, run the weight back up, and stop thinking about it. Reps counts stalls per weight and clears the counter the moment you break through, which is the right emotional model too: the wall stops existing as soon as you're past it. The full rule set is on how Reps decides your next set.