Open access resources are goods and services that are rival (they are diminished when exploited by someone) and from which it is difficult to exclude beneficiaries (they are not closed-off, gated, easily charged-for, so that prices can disclose value) and are largely unmanaged, or poorly managed. Open access resources are commonly over-exploited (they are rival) as people are motivated to take what they can, without penalty, therefore, they can be frequently degraded.