Dale had looked well off the pace as they trailed 1-0 at the break to Tom Craddock's 32nd-minute penalty, prompting a double substitution at the interval.
And the decision paid dividends as Joe Thompson promptly crossed for fellow substitute Adam Rundle to level matters with a clinical finish after 56 minutes and earn Rochdale a share of the spoils.
The Hatters bossed the first half with Ian Henderson, Kevin Gallen and Asa Hall all going close before Craddock broke the deadlock by blasting home from the spot after Nathan Stanton had pushed Chris Martin in the area.
Dale came back into it in the second half and after Rundle's leveller, the winger then played in Adam Le Fondre but Rochdale's leading scorer wastefully blasted over.
Le Fondre almost won it for Rochdale in the final minute only for Luton goalkeeper Dean Brill to save his close-range shot.