Realms of Arkania: Blade of Destiny

In order to pick locks you need:
1. Someone with a high lockpicking skill
2. Someone with an actual lockpick

If you can't find any lockpicks to purchase, I recommend heading to a temple and switching out your party members. I choose a pre-made rogue character from the list, and he joined with a lockpick on him.

Once you have a party member that can do the job, you need to find a door or chest to unlock. There are plenty of them scattered throughout dungeons, but if you're looking for a specific place, you can head to Upper Orcam and go inside the Dwarven Mine. There's a locked door straight ahead.

Save, then attempt to open it. Each time you either successfully open the door or fail and break your pick, just reload. It will count your progress each time. If you're having trouble getting the lockpick icon to pop up, try looking directly in the middle of the door, or slightly below that.

Either way, once you've successfully opened 25 locks, the achievement will pop.