Case Law, Under Section 1, Rule 10, CPC

O 1 R 10
The Court may at any stage of the proceedings either upon or without the application of either party and on such terms as may appear to the Court to be just, order that the name of any person who ought to have been joined, whether as plaintiff or defendant, or whose presence before the Court may be necessary in order to enable the Court effectually and completely, to adjudicate upon and settle all the questions involved in the suit, be added.

Only necessary or proper parties can be added. Not any other parties.
A 1951 M 665, A 1934 N 228

Persons indirectly or remotely interested are not necessary or proper parties.
1996 SCMR 781, 1996 CLC 678, P 1972 L 169, A 1941 FC 16, A 1943 A 289, 20 IC 658, 1996 CLC 456, P 1996 K 467, A 1918 PC 49

Trial should not be embarrassed by simultaneous investigation of unconnected controversies.
11 SWR 23 FB

Persons who have no interest should not be added.
PLJ 1975 SC 345, 2004 CLC 1567, 1994 MLD 1489, A 1937 M 200, A 1929 B 353,

Persons cannot be added as parties to add a new cause of action which does not concern the plaintiff at all.
PLJ 1985 SC 461, 1999 CLC 2077, 1992 CLC 700, 1984 CLC 286, 1979 CLC 891,

A person who has a champertous interest in litigation should not be added.
2004 MLD 1395, 1996 CLC 678, 1996 SCMR 781

Parties cannot be added after decree is drawn up.
A 1924 M 648

Mere fact that a person may, by some chance, become interested in claiming property adversely to plaintiffs is no ground for his being so impleaded because that would necessitate importation of facts not found in suit.
NLR 1992 Civil 250

Not made party if application to prolong litigation.
1992 CLC 1432

Not made party if application suffering from inordinate delay.
NLR 1992 AC 204, 1989 SCMR 1589, PLD 1980 Lah 804

Where rights of parties could be effectively determined in suit without impleading any other party and claim of parties inter se arose out of contractual obligation to which party sought to be impleaded was not a party, impleading of same would be neither necessary nor proper.
1988 CLC 2014