All of the locations of where you can get all skill tomes for all classes in Celtic Heroes
Breakdown of skills introduced in v4 Dragonfire Update
These are the locations where you can find skill tomes and rings for each zone.
Fingal's Cave: | Dunskeig Sewers: | Carrowmore Tunnels: |
Ice Blast | Skewer | Sharpen Weapons |
Longshot | Shadowstrike | Life Steal |
Bless | Defensive Formation | Shield Wall |
Shatter | Explosive Arrow | Fire Attunement |
Riposte | Stinging Swarm | Rescue |
Double Attack | Frostbite | Sanctuary |
Energy Harvest | ||
Rupture | ||
Double Shot | ||
Ice Attunement | ||
Expose Weakness |
In my experience farming in Fingal's Cave, any mob can drop a manual or a ring. I've found Greater rings from killing 1*s. Another thing I've found is that 5* bosses seem to drop a manual or ring 100% of the time. Also, they never drop anything below a greater ring. I've killed a good number of 5*s, as well as my friend, and always gotten drops following this.
Also See:
Sources:
GreybeardHalt, http://celtic-heroes.com/forum/viewtopic.php?f=4&t=36021