Guru's calculators enable users to test how their portfolios may hold up under adverse economic conditions and encourages users to focus on the most challenging results instead of overly optimistic projections (i.e., plan for the worst and hope for the best). Nest Egg Guru also allows users to quickly see how changing variables that are within their control (e.g., asset allocation, cost of living increase, savings and withdrawal strategies, etc.) may affect their results. All of this, they hope, is achieved in a friendly, intuitive design that better reflects the experience of real world investors.