USAR Official Rules & Regulations

5 – One Serve (U.S. Team Divisions at National Singles and Doubles Only)

The USAR's standard rules will be followed for all play except for the U.S. National Team Qualifying divisions played at U.S. National Singles and Doubles where only one serve is allowed. Therefore, any fault serve is an out serve, with a few exceptions [noted separately below, and within the text rules cited].

See Rule 3.9 Fault Serves

[Screens]
(i) . . . In one serve play, if a serve is called a screen, the server will be allowed one more opportunity to hit a legal serve, except if the serve is also defective for some other reason, such as being long or short. Two consecutive screen serves results in an out.

[Serving before the Receiver is Ready]
(j) . . . In one serve play, if a serve is made while the receiver is not ready as described in Rule 3.5(b), the server will be allowed one more opportunity to hit a legal serve.

See Rule 4.3 Fault Serves in Doubles

[Serve hits partner / Consecutive faults]
(c) . . . In one serve play only, if a serve hits the non-serving partner while standing in the box, the server will be allowed one more opportunity to hit a legal serve. Hitting the non-serving partner twice results in an out. Also consecutive faults – such as (i) a screen serve followed by hitting the non-serving partner or (ii) hitting the non-serving partner followed by serving while the receiver is not ready -- results in an out.