There are total 80 red gems that you need to collect in Shadows of the Damned to unlock High in Las Vegas achievement or trophy. 38 of these red gems are hidden throughout the Underworld and remaining 42 can be bought from the Christopher’s shop.
You can buy these gems using the white gems that you would collect throughout the game. Also, you need to collect them all in a single playthrough since there is no chapter select option available in the game. So, you would need to do a second run if you missed any of these hidden red gems.
Shadows of the Damned Red Gems Locations Guide
Act 2 – Take me to Hell
Red Gems #1-3
Location. There are three gems you can found underneath a bridge near Hangman’s Tavern.
Red Gems #4
Location. The place where you fight the demons trio summoned by Dark Hand. Look for a red gem behind behind the pillar at the far end of this place.
Red Gems #5
Location. In a small hut guarded by the baby demons near the opera poster.
Act 2 – What a Wonderful World
Red Gems #6
Location. As you jump from the second floor of the house into the area with a telephone ringing. Look for this red gem behind the pillar.
Red Gems #7
Location. Collect all the white gems in the chandelier and you will get it as a reward on the exit pathway.
Red Gems #8-9
Location. Defeat all the demons in the chandelier and you will get two red gems.
Act 3 – It’s A Bug Hunt
Red Gems #10
Location. Look for a red gem in the flowers to the left of Christopher.
Red Gems #11
Location. Look for this red gem in the side passage that is accessible at the start sewers area. Behind the strawberry in the alley that you need to retrieve to get past the baby demon gate.
Red Gems #12
Location. Locate a cracked wall stone wall right at the end of this level, look behind it and you will find this red gem.
Act 3 – My Dying Cuncubine
Red Gems #13
Location. Take the side path down to the gut wall at the start of the level. Look behind this gut wall for this red gem.
Red Gems #14
Location. Find the rocks lying around near the demon cages. Look behind the rocks for this gem, it’s difficult to spot.
Red Gems #15
Location. Find a fallen log in the Lakeshore. Look behind this fallen log for this red gem.
Red Gems #16
Location. Find the guts wall to the right of the cave that you come across at the end of the level. Look behind the guts wall for this red gem.
Act 3 – As Evil As Dead
Red Gems #17
Location. When the first Paula chase sequence starts, Look for a barrel next to the demonic shrine. This red gem is inside this barrel.
Red Gems #18
Location. This red gem is in the darkness so a bit tricky. Take the down path right to the pedestal with blue gem and you will come across it.
Red Gems #19
Location. As you are following Sushi Lamp, you will come across a house with a barrel lying next to it. This red gem is inside that barrel.
Act 4 – Great Demon World Village
Red Gems #20
Location. Collect all the 50 white gems in this level.
Act 4 – Ghost Hunter
Red Gems #21
Location. In the Hall of Gluttony before you walk across the bookshelf bridge, turn right and search the shadowy book stacks. You will find this red gem at the end of the farthest corridor.
Red Gems #22
Location. Break the second glowing wall hidden among the bookshelves to reveal a room full of crates. You need to break open these crates to get this red gem. There are also few bottles of Sake, consider it a bonus.
Red Gems #23
Location. After the Sushi Lamp makes its first turn, continue moving forward and turn right when you come across a book shelf. You will find the red gem at the end of the corridor.
Act 4 – Great Demon World Forest
Red Gems #24
Location. Collect all 50 gems in this level.
Act 4 – Suburban Nightmares
Red Gems #25
Location. You will find this red gem inside the barrel lying left to the gut wall at the end of the cave.
Red Gems #26
Location. Look for a cracked stone wall to the left of fireworks launcher. You will find this red gem behind this cracked stone.
Red Gems #27
Location. Look for this gem inside the outhouse behind Christopher’s shop. The house is covered in darkness vines.
Act 4 – Justine For All
Red Gems #28
Location. Collect all 50 white gems in this level.
Act 5 – Twelve Feet Under
Red Gems #29
Location. There is a barrel behind the pillar in the room where you first encounter Electrodiode demon. Look inside the barrel for this red gem.
Red Gems #30
Location. Find a crate in rotunda, look inside to get this gem.
Red Gems #31
Location. You will find it inside the barrel in the darkness filled room with core destroyed with Skullbuster Grenade.
Act 5 – Different Perspectives
Red Gems #32
Location. You will find it on the bottom of the first red block in Moor Pu Dekcuf.
Red Gems #33
Location. After you clear the bridge of demons and lift the darkness, a set of stairs will connect the blocks. Walk down them and you will find a red gem at the base.
Red Gems #34
Location. Continue down another set of stairs after #33 and you will find second red gem in the area.
Red Gems #35
Location. Look for it on the bottom of the large block with stairs near the end of the Moor Pu Dekcuf.
Act 5 – Castle of Hassle
Red Gems #36
Location. Kill the two demons in the Skullblaster Pachinko machine.
Red Gems #37
Location. Look for a barrel near the spinal stair case. You will find it inside this barrel.
Red Gems #38
Location. Inside the Madness Maze room with corpses hanging from the hooks, look for a barrel. The red gem is inside this barrel.
If you face any trouble locating any of these red gems, you can ask me in comments, and I will try to give you more detailed insight on that while improving the guide on go.