"The Robin" was Barney Stinson's most significant play from his infamous Playbook in How I Met Your Mother. Here's an explanation of Barney's wedding plan and how it played out over the course of multiple episodes in HIMYM season 8.
The Playbook was initially created as part of Barney's (Neil Patrick Harris) notorious scams in picking up women; he revealed the physical tome in How I Met Your Mother season 5. The book served as a compilation of strategies that Barney used to successfully win over women. Lily (Alyson Hannigan) wasn't too happy with how Barney manipulated innocent people with his plays, so she threatened to publish it. The book then disappeared for a bit, but it made its grand return in season 8 as part of Barney's final play.
In a season 9 flashback episode, it was revealed that Barney ran into the "Mother," who convinced him he was still in love with Robin (Cobie Smulders). In an effort to win her back, Barney created his ultimate play, The Robin. The secret plan consisted of 16 steps, some more involved than others. The steps played out over the first half of season 8. But it wasn't just about winning Robin back, it was about finding a way to keep her forever:
Step 1: Admit to yourself that you still have feelings for this girl.
Step 2: Choose the completely wrong moment to make a drunken move after hanging out at a strip club… and get shot down on purpose.
Step 3: Agree that you two don’t work, locking the door on any future you could have together, which will drive Robin nuts.
Step 4: Robin goes nuts.
Step 5: Find the person who annoys Robin most in the world and ask for her help. Explain everything to Patrice and hope she agrees to help.
Step 6: Check with your doctor about possible broken ribs.
Step 7: Pretend to be dating Patrice.
Step 8: Wait until Robin inevitably breaks into your place to find The Playbook and show it to Patrice, which you’ll monitor via the hidden cameras you have in your apartment.
Step 9: After Patrice “finds” The Playbook, have your first “big fight.”
Step 10: Prove your loyalty to Patrice by burning The Playbook, and actually burn it. You don’t need it anymore.
Step 11: Because your friends have no boundaries, they’ll inevitably have an intervention for Robin, which you’ll monitor via the hidden cameras you have in Marshall and Lily’s apartment.
Step 12: Tell only Ted about your plan to propose to Patrice.
Step 13: Wait and see if Ted tells Robin. And if he does, it means your best bro in the world has let go of Robin and has given you his blessing.
Step 14: Robin arrives at her favorite spot in the city and finds the secret final page of The Playbook… the last play you’ll ever run.
Step 15: Robin realizes she’s standing underneath mistletoe.
Step 16: Hope she says yes.
The Robin's first step took place in the episode titled "Splitsville." Barney forced himself to admit to Robin in public that he's still in love with her. In the following episode, Barney decided to kiss her at the worst possible time, which became his second step. From there, Barney's steps were meant to purposely drive Robin crazy. He then moved to the next stage of The Robin which involved asking for help from the person who annoyed Robin the most–Patrice (Ellen D. Williams).
Barney let Robin believe that he was dating Patrice in the hopes that she would truly lose her mind. It worked: in the episode titled "The Over-Correction," Robin broke into Barney's apartment and found the Playbook with the intention of revealing Barney as a womanizer. Robin's plan backfired but it perfectly played into Barney's next set of steps. He staged a fake fight with Patrice regarding the Playbook and pretended that he would get rid of it to stay with Patrice. This made Robin lose her mind completely, resulting in her intervention.
The final steps of The Robin play out over a two-part episode titled "The Final Page." Barney tested Ted (Josh Radnor) to see if he still held feeling for Robin as well. Ted ultimately urged Robin to go after Barney which meant he could continue with his last few steps. Barney lured Robin to her favorite spot in the city where she found the last page of his Playbook. When she flipped the page over, the final step of The Robin was revealed. Robin read the words, "hope she says yes" as Barney appeared kneeling on one knee. The pair eventually got married but, as revealed in the controversial HIMYM series finale, the relationship doesn't last. It's a shame considering the How I Met Your Mother spent so much time proving that Barney was a changed man and that he and Robin are destined to be together, but fans will always have "The Robin".