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by Kingsley Hopking

Reaction time in games

By gaining an understanding of what is a fair amount of time for players to react to events within video games, there is potential to apply this knowledge to ensure that the difficulty of interaction between players and enemies are possible for progression.

It could be argued that for a reaction input to be made there are multiple stages should be taken into consideration; firstly the amount of time it takes for the player to perceive an action in the environment, secondly how long it takes for a user to register an action these can be defines as the processing stages. finally how long it takes for the software or game to register the action the user made this is know as the response (Bjørklund, 1991).

It has been observed that the response time to perceived change in the environment is around 60 milliseconds (Posner, 2005). From this the amount of time to register an action is begun, depending on the amount of choices being presented to the player the decision to reaction time can vary from 282 milliseconds for a single choice. This time increased to 420ms when the user was presented with four different choices (Deary, Liewald and Nissan, 2010).

Input latency from the hardware presents a start and end buffer 8.5ms from the refresh rate from the display and 8ms from the keyboard, the physical keys having input delay due to them moving back to to a depressed state, this can add latency from 15ms to 60ms depending on the keyboard (Limmen, 2018). This presents a first input with pressed buffer of 16.5ms with repeated actions

an increased buffer. Considerations on this change due to the speed that the hardware updates (polling rate). As the polling rate increases the latency is reduced, the latency values used within this study use the frequency of standard hardware. With the information presented, it could be argued that when designing with reaction time in mind it is important to consider, The time it takes for players to perceive a changes in the environment, followed by the complexity of the interaction and factoring in the physical hardware limitations.

From the numbers found throughout this research it could be considered that the minimum amount of time for a single choice action to be fair to a user should be 298.5ms[1] with this number increasing to 496.5ms[2] during multiple choice actions.

[1][2](environment change) + (choice decision reaction time) + (hardware limitations) = (minimum amount)


Deary, I., Liewald, D. and Nissan, J. (2010). A free, easy-to-use, computer-based simple and four-choice reaction time programme: The Deary-Liewald reaction time task. Behavior Research Methods, 43(1), pp.258-268.

Bjørklund, R. (1991). Reaction Time and Movement Time Measured in a Key-Press and a Key-Release Condition. Perceptual and Motor Skills, 72(2), pp.663-673.

Limmen, C. (2018). What influences keyboard input speed. [online] Wooting developer blog. Available at: speed/ (Accessed : 12 October 2019).

Posner, M. (2005). Timing the Brain: Mental Chronometry as a Tool in Neuroscience. PLoS Biology, 3(2), p.e51.