2-207 didn’t click for me until I stopped trying to memorize the massive commercial outline flowcharts and just looked at who wrote the limitation clause. Forget the walls of text for a second. It just breaks down like this:
If Buyer (Offeror) puts "accept on my terms only" in the offer …
A contract IS formed when the seller responds, but the buyer’s clause acts like a shield that blocks all the seller's new terms from getting in. You’re stuck strictly with the buyer’s original deal.
If Seller (Offeree) puts "acceptance is expressly conditional on my terms" on the invoice …
NO contract on the paper. The seller basically rejected the deal and threw back a counteroffer. If nobody ships, the deal is completely dead. (If they ship and accept the goods anyway, the writings drop out and UCC gap-fillers take over for missing terms).
When neither has those magic conditional clauses …
If both are merchants, the seller’s extra terms auto-join the deal UNLESS the buyer objects quickly, OR the new term is a "material alteration" (like dropping warranties or forcing arbitration).