Kick tolerance is a key and fundamental concept used in well design. It defines the appropriate number and setting depth of casing strings that are required to achieve the drilling objectives. It is also used during drilling to determine whether it is safe to continue drilling or if there is a need to run a casing string. Alternatively, it is used to indicate whether it is safe to circulate a kick out of the well or whether bullheading is necessary. During development of a new well control system, a thorough review of the fundamental concepts involved was carried out, and, in relation to kick tolerance, a few misconceptions were identified. Among those misconceptions are issues related to the calculation of the kick volume on bottom when a BHA is present, the effects of friction losses on the wellbore annulus and choke line, and confusion between kick tolerance and maximum allowable pit gain, derived from the additional formation flow into the wellbore after the well is shut in (afterflow). Another important misconception is the assumption that an approach utilizing a single bubble model and ignoring effects of temperature, influx density and gas compressibility (z) factor in the final calculation will always result in a conservative solution. This paper utilizes four example wells to demonstrate the effect of each component on the final kick tolerance calculation. In order to make it easier to understand, each effect is calculated individually using the same single bubble model that has been historically used. The results show that some components have more impact than others, and the consequence is not always in the same direction. Additionally, the effects on deepwater wells are more dramatic due to the long choke line. Therefore, generalization and simplification of the kick tolerance calculation in well design is not possible.