Blue Gems are one of the gems in the Gemcraft Series. It has the power to slow down oncoming monsters.
Gemcraft Chapter 1
Towers
The blue gem slows down an enemy, causing it to move at reduced speed for a certain amount of time depending on the gem grade.
Gemcraft Chapter 0
Gemcraft Labyrinth
All 12 Grades of the Blue Gem in Gemcraft Labyrinth
Towers
Blue Gems placed in towers are strategically placed around other gems. The monsters will slow down and be hit by more attacks. Below are the statistics without any amplifiers.
Grade 1 Gem- Slows 18% for 4 seconds
Grade 2 Gem- Slows 22% for 4 seconds
Grade 3 Gem- Slows 28% for 4 seconds
Grade 4 Gem-
Traps
Blue Gems placed in traps increase their power greatly. The percentage of slowing for a blue gem can exceed 100% (which is more common in a trap), but does not slow it any more than usual. However, with increased percentage usually comes increased time it slows.
Grade 1 Gem- Slows 32% for 4 seconds
Grade 2 Gem- Slows 41% for 4 seconds
Grade 3 Gem- Slows 51% for 4 seconds
Grade 4 Gem-
Gemcraft Chapter 2 (Chasing Shadows)
"Slow" skill tome location is on field K6.
Pre-v1.1.0:
Slowing gems work much like before, slowing for a variable % of speed for a fixed period of time. Bloodbound and Poolbound gems, as well as Amplifiers, increase slow %, but not slow duration. Traps increase duration but not %. Skill points placed in slowing skill increases slow %.
v1.1.0+:
Slowing gems reworked to be much more useful overall. Slow % now has slower growth rates. Bloodbound, Poolbound, Amplifiers and Traps work the same as before, but skill points in slowing skill now increases duration rather than %, allowing for gems that can easily slow by 90% for 2-3+ minutes on a single hit.
Ideal Positioning
Towers
If you have multiple blue gems, space them evenly around the path to try to keep the monsters slow for as much of the time as possible. Focus on the areas directly in front of your most heavily defended areas.
Traps
A blue trap should be placed directly before your most heavily defended area. They can also be used directly in front of an orange mana trap. This increases the amount of mana you can draw from each monster by exposing them to the mana drain effect longer.