Okla. Stat. tit. 12, § 12-178: Service on some of several defendants

Where the action is against two or more defendants, and one or

more shall have been served, but not all of them, the plaintiff may

proceed as follows:

First. If the action be against defendants jointly indebted

upon contract, tort, or any other cause of action, he may proceed

against the defendants served, unless the court otherwise direct;

and if he recover judgment, it may be entered against all the

defendants thus jointly indebted, so far only as that it may be

enforced against the joint property of all, and the separate

property of the defendants served; and if they are subject to

arrest, against the persons of the defendants served.

Second. If the action be against defendants severally liable,

he may, without prejudice to his rights against those not served,

proceed against the defendants served in the same manner as if they

were the only defendants.