Introduced in Pokemon Crystal, the Battle Tower is a place for trainers to test their skill against tough opponents. In Pokemon Diamond and Pearl this is the same. There are a few changes though. There will only be LV50 Pokemon battles here, but even if your Pokemon are over LV50, they can still enter; their level will just be temporarily reduced back down to 50, but after finishing the challenge, they'll be back to normal.
Like in other games, you get Battle Points after clearing the challenge. These can be traded for some rare and valuable prizes.
Like in the Battle Frontier, you are not allowed to enter Pokemon like Mewtwo. Below is a list of Pokemon that can't be entered.
Once you enter, you'll see three counters. The far right one is for Wi-fi and battles over the Internet. Here, you can register a trainer over the Internet and you can face them and their Pokemon in the Battle Tower randomly.
The center door is for the normal one-on-one and two-on-two battles. This works exactly like the Battle Towers in the 3rd generation games; the difficultly level increases for each row of victories. Like in Pokemon Emerald, the leader of the area comes out to challenge you; this is only in single battles though.
The Tower Tycoon Palmer will challenge you after 20 straight wins. Below are his Pokemon.
After 48 straight victories, the Tower Tycoon will challenge you to a battle again. Below are his Pokemon.
The final booth is for doubles battles. Here is where you can team up with your friends or trainers around the world in a double battle either against the computer or somebody else. If you don't have a partner to team up with, you can head into a room full of trainers. These trainers though might look familiar to you. They are trainers that you have helped out and that have teamed up with you. They will have a whole heap of Pokemon. Below are the people and their specialty.
Cheryl from Eterna Forest
She uses Pokemon with high HP and high Special Attack
Mira from Wayward Cave
She uses Pokemon with high Special Attack
Riley from Iron Mountain
He uses Pokemon with high Attack
Marley from Victory Road
He uses Pokemon with a high Speed
Buck from Stark Mountain
She uses Pokemon with high Defenses