Strategic Synergy

Variable interval reward schedules provide a reward after a roughly consistent amount of time. This tends to create a reasonably high level of activity over time, as the player could receive a reward at any time but never the burst as created under a fixed schedule. This system is also more immune to the nadir right after the receiving of a reward, but also lacks the zenith of activity before a reward in unlocked due to high levels of ambiguity.

Example: Wait roughly 30 minutes, a new weapon appears. Check back as often as you want but that won’t speed it up. Generally players are bad at realizing that.

(Source: SCVNGR Playdeck)