Your short put is in the money, expiry is close, and you have two honest choices: roll the position out (and maybe down) for a credit, or let the shares come to you. Both are legitimate. The mistake is not choosing — rolling on autopilot every time the strike gets touched.
What a roll actually is
A roll is two trades wearing one name: you buy back the put you're short and sell another one at a later expiry, usually at the same or a lower strike. Done for a net credit, it extends the trade and adds premium. Done for a debit, it's usually a quiet way of refusing to admit the trade went against you.
The clean rule: only roll for a net credit. If you can't get paid to extend the trade, the market is telling you the position has deteriorated past the point where rolling helps.
When rolling is the right call
Roll when the thesis is intact and the move feels temporary — a market-wide dip dragging your stock along, an overreaction to noise, an IV spike that makes the new short put unusually rich. In those spots you're being paid well to wait, your effective basis keeps dropping, and the extra weeks are genuinely useful.
Rolling down and out is especially strong when you can lower the strike and still collect a credit: you've reduced your assignment price and gotten paid for it.
When assignment is the better trade
Take the shares when you'd buy the stock today anyway. That was supposedly the premise of the whole trade. If the stock is sitting just below your strike with a stable thesis, assignment converts you to the covered-call side of the wheel, where you can often collect more premium than another defensive roll would pay — and your basis already reflects every credit you've banked.
Take assignment, too, when rolling only works for a debit, or when you notice you've rolled the same position three times. Three rolls is not a strategy; it's a loss you're amortizing.
Keep score or you'll fool yourself
A rolled position hides its history. The only way to know whether your rolls are making money is to track the chain — every buyback, every new credit, every day of capital tied up — as one continuous trade. If your annualized return on the chain keeps dropping with each roll, the market already answered the question.