The Obsidian Sword is a melee weapon that does 30 damage points.
You can create it in your Crafting Menu (default key "Q") or at Crafting Tables (that still exist in older worlds created before September 2015) after unlocking the according crafting recipe by crafting or taking a Stone Sword. Very rarely you can find Obsidian Swords in Iron Treasure Chests on the underground Lava Layer (since R22) or as pet-harvest from Keepas.
To craft one Obsidian Sword, you'll need
- 3 Obsidian (bars) made in a Forge from Obsidian Ore
- 2 Stone Rods made of Stone, Limestone or Bedrock in a Processor
- 4 Miru Eyes obtained from Mirus that spawn on Bedrock in shallow Caves in the Fossil layer, and also on Siltstone in the Stalactite layer underground. Such eyes can also be obtained from Corrupted Mirus from their Loot Bags. Please note that blue Arctic Miru Eyes cannot be used for this crafting recipe
- 4 Bones
Crafting/taking the Obsidian Sword is the unlocking requirement of the crafting recipe for the Iron Sword.
To use any sword you must right-click on it in the inventory which will place it into the weapon-slot next to your character's portrait. Afterwards you can switch between weapon-mode, tool-mode and harvest-mode with TAB (default key).
Whenever you hit a creature with a sword, the weapon will lose a bit of durability until it falls apart completely. The durability is indicated by a bar over the icon of the sword - in your equipment slot next to your character's portrait as well as on the main screen visible over the weapon slot. You might want to be prepared and take a new sword with you if your current one already hasn't much durability left!
- In real life, Obsidian is extremely sharp, yet also extremely brittle. Chibbing(or clubbing with the blunt areas of a sword) with an Obsidian sword in real life would result in it breaking. For this reason, real life Obsidian blades tend to be shorter than 30 cm, or 12 inches.