Positive is a Specification of the Outcome Property.

A Positive Outcome when a Resource is spent to improve the players situation; building buildings and units, buying helpful items, placing skill points, converting resources etc. All of these has a positive effect. Note that a resource can have both negative and positive outcomes. Mana in Kings Bounty, for instance, can both be used to damage enemies and heal friendly units.

Determine whether a resource have negative or positive is very game-specific, but labeling the resource with positive or negative gives a general idea.

Always found in Archetypes:
Action, Currency, Material, Physical, Potion, Skill Point, Rune

Occasionally found in Archetypes:
Mana, Rage

Found in Games:

Game - Bioshock 2 (Eve, adam, first aid kit, hypo)
Game - Crysis 2 (suit energy, nano-collection)
Game - Deus Ex; Human Revolution (energy, credits, praxis points, alcohol/food)
Game - Diablo 2 (energy, stamina, potions, gems/runes, identify scrolls, town portals, stat points, skill points)
Game - Farmville (farmcoins, farmcash, consumables (one-use), bushels, building materials)
From Dust (Elements)
Game - King's Bounty; Armored Princess (mana, unit abilities, unit action points, runes, potions)
Game - Kingdoms of Amalur; Reckoning (skill points, ability points, fate, mana, gems, gold, potions, lockpicks, repair kit)
Game - League of Legends (runes, mastery points, hero skill point, riot points, influence points, consumables, renektons fury, vladimirs tides of blood, vladimirs health, shyvanas fury, akalis essence of shadow, karmas mantra, ahris soul eater, dr. mundos health, energy, mana)
Game - Majesty (gold)
Osmos (Matter)
Game - Plants vs. Zombies (sun, coins)
Game - Puzzle Quest 2 (gem reserves, gold, materials)
Game - Revenge of the Titans (turret quantity, power-ups, dollars)
Game - StarCraft II (minerals, vespene gas, energy, research point, credit)
Game - Team Fortress 2 (Metal)
WordFeud (Letters)
Game - World of Goo (Goo, Time Bugs)
Terraria (potions, perpetual resources, coins, resources gained with a pickaxe, non-consumable, potions, mana)