Adventurers that have been playing through Blizzard's Heroes of the Storm have made their voices heard, regarding the game's current bonus trickle XP system. The mechanic that would help slightly boost XP for teams that have fallen behind is being sent back to the drawing board in favor of a new idea called the 'Underdog Bonus.'
Rather than trickle additional XP to teams three or more levels behind at a higher rate, those teams will now have to earn that bonus XP. Teams behind by at least one level will earn additional XP for taking down an enemy hero, with additional XP allocated until team levels even up. Likewise, teams that are ahead will see an XP reduction for every takedown.
"You can also expect larger level gaps to occur in part because the Underdog Bonus places more control into the hands of your team, and offers additional opportunities to eke out a comeback over the course of a game," explains the Battle.net post. "If you're ahead in levels, you'll need to remain focused, and give up as few takedowns as possible to maintain the lead while you work toward the enemy Core. If your team finds itself behind, you'll have to decide how best to close up that level gap. Do you take an enemy Fort, split up to soak XP in-lane, or dig in your heels and make life as difficult as possible for your opponents in hopes of scoring a few takedowns?"
Like the previous bonus trickle XP system, this is subject to change as Heroes of the Storm's technical alpha continues. Blizzard adds that they're just as likely to revert back to the previous system, depending on player feedback.