Halloran’s Confidence Interval

4th-level Analytics & Forecasting

Casting Time: 1 action
Range/Area: Self
Components: V, S, M (a range of values, stated with a precision the underlying data does not support)
Duration: Until the actual result falls outside the stated range
Classes: VP of Strategy, Director of Data, Analyst

You state a numerical estimate bounded by an upper and lower value. For the duration, the estimate is treated as accurate regardless of the true result, so long as the true result falls within the stated bounds. If the true result falls outside the bounds, this spell does not end in failure; instead, you may immediately recast it with the range widened just enough to contain the true result, at no additional cost and without expending an additional spell slot. If you have an active Halloran Principle, you may instead spend 1 point of Conviction to recast it this way even after the normal window for a free recast has closed.

This spell can be recast in this manner an unlimited number of times. Each recasting is presented as a refinement of the previous estimate, never as a correction of it.

At Higher Levels. When cast using a spell slot of 5th level or higher, the recast range may be stated in a unit not previously disclosed (e.g. switching from absolute figures to percentage variance), further obscuring how far the original estimate had to move.

Flavor: “We’re now forecasting a range of $180-220M, down from our original guidance of $240-260M, reflecting continued confidence in our core business.” — investor letter