Effect is a specification of the produces property.

Effect is something that affects the game through a non-physical presence. Effect is fairly nondescript, as an effect can be any number of things, as it incorporates all actions that does not create a virtual, abstract or object. It can be the effect from firing ammo, gaining a buff from placing a skill points, casting spells, or any number of attacks and actions.

Always found in Archetypes:
Rune, Skill Point, Rage, Potion, Mana, Health, Ammo

Occasionally found in Archetypes:
Action, Currency

Found in Games:
Game - Bioshock 2 (Eve, Ammo, Adam, Hack darts, Hypo)
Game - Crysis 2 (Suit energy, ammo, grenades, nano-collected)
Game - Deus Ex; Human Revolution (energy, credits, praxis points, alcohol/food, ammunition/grenades)
Game - Diablo 2 (energy, stamina, arrow/bolt, potions, gems/runes, grenades, identify scrolls, town portals, stat points, skill points)
Game - Farmville (farmcoins, farmcash, consumables (one-use), bushels)
Game - King's Bounty; Armored Princess (mana, dragon rage, unit abilities, unit action points, runes, potions)
Game - Kingdoms of Amalur; Reckoning (skill points, ability points, fate, mana, gems, gold, potions, shadow prisms, arrows, lockpicks, repair kit)
Game - League of Legends (runes, mastery points, herro skill point, riot points, influence points, consumables, renektons fury, tryndameres, rage, vladimirs tides of blood, vladimirs health, shyvanas fury, akalis essence of shadow, karmas mantra, ahris soul eater, caitlyns headshot, dr. mundos health, energy, mana)
Game - Majesty (gold)
Game - Plants vs. Zombies (sun, coins)
Game - Puzzle Quest 2 (gem reserves, action points)
Game - Revenge of the Titans (power-ups)
Game - StarCraft II (minerals, vespene gas, energy, nuke, research pint, credit)
Game - Team Fortress 2 (ammunition, ubercharge)
Game - World of Goo (Time Bugs)
Terraria (potions,