Jarrold is best known for the feel-good Anglophile fantasies Kinky Boots and Becoming Jane, and A Royal Night Out is a genteel, succinct venture in the same vein. With little context for the princesses' lives during the war (or those of the countrymen who dance and drink beside them), the film relies heavily on the coltish charms of its young leads, and Powley's effervescent, well-timed performance as the younger princess (she calls herself "P2") is skillful enough to bring out the screwball latencies in an otherwise bland screenplay. Alas, there's no John Hughes around to lovingly shape the teenagers' escapades; this romantic caper's only antagonists are the girls' stiff, mustachioed escorts, and the script cheekily subjects the younger princess to some rather unfair creative liberties, at one point having her pass out drunkenly in a wheelbarrow.
Minor indignities aside, the film is mostly distant with politesse. Gadon is a delicate and dignified future monarch, while Emily Watson and Rupert Everett do their best in the tiny roles of Queen Elizabeth and King George VI -- Everett soldiers on in makeup that makes him look like Ted Cruz. All together, the pack of them feel a mite too sincere and dewy-eyed to have just come through a war.