Prepare a transparent entrant list before using a random draw.
Use the Giveaway Picker alongside this illustrative example.
A practical example
Suppose a list contains Alex, Bea, Chen and a second Alex. If the duplicate is the same eligible person and each person should have one chance, remove it before drawing. If two different entrants share a display name, replace those names with distinct eligible entry IDs rather than merging them.
Check the result
Record the eligibility rule, closing time and redraw conditions before selecting a winner. Preserve the final list and draw result so a later question can be answered without rerunning until a preferred name appears.
Try a comparison
Check the final list before drawing multiple winners. Removing selected list entries prevents the same entry from winning twice, but two duplicate lines for one person still create two entries. List hygiene and the selection algorithm solve different problems.
What this does not establish
The picker does not verify identity or legal eligibility. A random interface is not independent certification of a regulated promotion.