Ticks
From RS Wiki
A tick is a dimension update. During the tick everything that was supposed to happen on the dimension current turn is processed, like matches simulation, contract renewals, wages payment, etc. After the tick the dimension turn will be incremented by 1. If the current turn is 144 we'll have what is called the season tick, where a season change happens, with new cup draws, ranking updates, board expectations generation and much more.
During the tick it is not possible to enter a dimension. A progress bar is displayed in the dimensions list screen representing how much of the tick has been processed. It is not very accurate yet, but gives you a general idea of the overall progress. Ticks can take just a few minutes or more than half an hour, depending mostly on how many official matches are being played, as match simulation is the most time consuming task during the tick.
