How to Get Exp. Share in "Soul Silver"by Mitch Reid ; Updated September 22, 2017
In “Pokemon SoulSilver,” every time you use a Pokemon in battle, you gain experience points. These points eventually add up, allowing your creatures to grow and reach new levels. The key to building a balanced team is to alternate which Pokemon you use in battle; however, if you have the Exp. Share item, even the Pokemon not on the front line have a chance to grow. You acquire the item after you complete a series of tasks.
Travel to Mahogany Town, a small town east of Route 42.
Go north through Route 43 until you reach the Lake of Rage.
Surf into the water and engage the Red Gyarados in the middle of the lake.
Defeat the Red Gyarados to gain the Red Scale item.
Talk to Lance, the Dragon-type trainer of the Elite Four, on the shore.
Go to Route 30, which is north of Cherrygrove City.
Visit Mr. Pokemon’s house on the northern end of the route.
Trade him the Red Scale for the Exp. Share.
Give the Exp. Share to the weakest Pokemon on your team so it can gain experience without being in harm’s way. Once that Pokemon’s level is equal to the rest of your team, give the Exp. Share to a different team member.
You can win additional Exp. Share items in the Goldenrod Lottery. Every day, visit the receptionist in the Goldenrod Radio Tower. If she finds three digits of your Trainer identification numbers match the day’s lottery number, you will receive the Exp. Share.
Whether you knock out or capture the Red Gyarados, you will receive the Red Scale. If you intend to capture the Gyarados, save the game before you engage it. Restart the game and return to the save point if you accidentally knock out the rare monster during battle. Even if you don’t need it for your main team, Gyarados is handy because it can learn the Hidden Machine techniques, such as Surf, Waterfall and Strength, which will aid you in your travels.