Synthesis or Fusion is a system in Counter-Strike Online.
Overview
Synthesis system allows you to combine existing material items to obtain new items. Each item's crafting recipe determines the type and quantity of materials required.
- Synthesis Method
- If you have synthesisable material items in your inventory, they will be automatically added. Select the desired item and begin synthesis!
- Any material items used for synthesis will disappear.
- The material item will be automatically selected from your inventory.
- Items currently equipped or in use cannot be used as materials.
Synthesis Item
- Giga Break LE
- Main article: Giga Break

A weapon that controls and releases infinite power. However, it cannot be perfectly controlled, so only a limited amount of power can be used. Consecutive basic attacks release energy. Swinging the weapon twice in succession creates Overflow-Alpha, allowing for a brief period of enhanced basic attacks. Using charged special bullets to create Overflow-Beta allows for extended periods of enhanced attacks. Additionally, a Wingman protects the user in Zombie Mode and Zombie Scenario Mode.
- Synthesis Recipe: If you possess duplicate Giga Breaks, you can use the extra Giga Break as a synthesis material to obtain Giga Break LE.
- This item has a different appearance and is identical in performance to the original Giga Break.
- This recipe consumes only one extra Giga Break to be converted to the LE version.
- Epic Lucky Ticket

An Epic Lucky Ticket that allows you to select a historical Epic Weapons or an Epic Edition weapon.
- Synthesis Recipe: 3 Red Envelopes
- Unused tickets will be deleted during maintenance on April 2nd (Thursday).
- (Synthesis Material) Red Envelope

A red envelope that allows you to obtain an Epic Lucky Ticket. Fusing 3 red envelopes will yield 1 Epic Lucky Ticket that allows you to select a historical Epic weapon or an Epic Edition weapon.
- Red Envelopes can only be obtained during the event period.
- Unused envelopes will be deleted during maintenance on April 2nd (Thursday).
- Obtainable from Epic Decoder at 0.30% chance.
- Giga Vision Glass

Glasses embodying the light of Giga Break, worn on the head.
- Synthesis Recipe: 5 Glass Fragments
- (Synthesis Material) Glass Fragments

Glass Fragments that can be used to obtain Giga Vision Glass (Unlimited). Synthesize 5 Glass Fragments to obtain Giga Vision Glass (Unlimited).
- Glass Fragments can only be obtained during the event period.
- Unused Glass Fragments will be deleted during the maintenance on April 2nd (Thursday).
- Obtainable from Epic Decoder at 6.090% chance.