Dungeon crawling tips

Use checkpoints (save points) when you find them; there are no consequences for leaving Jails (dungeons) at any time.

Enemies (respawn (be brought back to life at a checkpoint after death)) only due to a high security level or when you exit and reenter jails.

Completing the story in a jail does not prevent you from returning later to find missed chests or Dire Shadows (powerful enemies).

The security level increases when you are spotted and ambushed by enemies. In Merciless difficulty, it increases the second you are seen and more so when ambushed.

The best approach for stealth missions is to use Joker's special abilities to shoot enemies in your path before they can spot or ambush you.

Always pick up items you find, as they can be useful when sold.

Do not worry about chests you cannot open; you will be able to open them once you unlock the Bond Skill for it. Some chests may require request completions.

Take advantage of cover (press the cover button to crouch behind walls or objects) points and Phantom Dashes (quick movement options), both in and out of battle, as they are useful tools.

Use your Third Eye ability to find hidden cover points and other items you might otherwise miss.

Use the minimap (radar) to keep track of your location and identify Treasure Demons, which have different movement patterns than regular enemies.