Lawyers prevent improper joinder by first preparing a simple matrix linking each cause of action to the correct facts, parties, and reliefs, ensuring only claims arising from the same transaction or common legal/factual issues are combined. Before drafting, they verify necessary and proper parties, avoid mixing unrelated facts, keep each claim in a separate, clearly labeled section, and include a brief explanation of why the joined claims belong together. They also check jurisdiction, limitation, and valuation, attach documents that show the connection between claims, and add a fallback prayer for separate trials or addition/removal of parties so any later defects can be corrected smoothly and without delaying the case.
