Green Eco is among the most commonly recurring Eco's of the Jak and Daxter games, debuting in Jak and Daxter: The Precursor Legacy and appearing in all console titles so far. It is generally the Eco of Healing and Nature, either acting as part of the health system or as part of the puzzles in forest areas (in which they are used for healing anyway).
Samos Hagai is the Sage of Green Eco.
 Jak and Daxter: The Precursor Legacy
In Jak and Daxter: The Precursor Legacy Green Eco operates primarily as the unit of health for Jak. Jak has three slots of health, with 50 small pieces or one big piece of Green Eco needed to regenerate each one, with the abilty to store an extra, which will automatically fill a slot when Jak suffers damage. Green Eco is dropped from enemies and crates in varying amounts, and can also be found in vents, such as those kept by Samos on Sentinel Beach. The vents restore Jak to full health and give him 50 extra pieces of eco.
In the Precursor Basin, Green Eco is used to purify a field of Dark Plants. By using the Zoomer, the player must pick up Green Eco (by means of a Green Eco Vent) and run through the field of Dark Plants until they are all gone (this earns the player a Power Cell).
 Jak II and Jak 3
The functions of Green Eco in Jak II and Jak 3 are basically the same; rather than being available in small orbs, they are available in small boxes with a + sign on them. These work with the new health system perfectly as they restore 2 health points per box. In Jak 3, however, Green Eco has another use; in Haven Forest, it is used, again, to purify Dark Plants. The player must use the Jetboard and collect Green Eco to purify these Dark Plants.
 Jak X: Combat Racing
Green Eco is what measures the damage on your vehicle in Jak X: Combat Racing. There are little power ups around the tracks that fix the damage done to your car via other peoples' weapons, or big falls and crashes.
 Jak and Daxter: The Lost Frontier
Green Eco again plays a central role as it provides health for both Jak and Dark Daxter throughout the game. There are more purposes of Green Eco throughout, such as being fuel for planes, and providing ammunition for the new Gunstaff mod (the Lobber).
At the beginning of the game, Jak and Daxter find a Green Eco Crystal which can convert Dark Eco into Green Eco. Using this technology, Keira can convert Dark Eco into other types of coloured eco, supplying Jak with eco power-ups, including some Green Eco power-ups which involve increasing health, draining health, and strengthening Green Eco powers (Eco Shield and Eco Build).
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