What is lucky egg?

A lucky egg in Pokemon diamond/pearl is an item held by wild chansey. they apear exclusively in the grassy areas of route 209 and 210. every chansey you encounter has a 30% chance of holding an oval stone a 5% chance of holding a lucky egg and 65% chance of holding nothing. the best way to get the lucky egg is by entering a Pokemon chain on chansey with the poke radar, and having a Pokemon with the ability "frisk" as your lead Pokemon. this will tell you if the chansey is holding the desired item. then you either use a Pokemon that knows pluck to steal it or you capture the chansey.