Create a rule called The Exit:

The Exit consists of all cells with a value of “Exit”, and all cells with that value have a colour of Purple. Once a cell’s value is set to the value of “Exit”, that cell can never have its value changed, nor its colour changed.

Each Runner has a non-negative integer called Number-Crunches which is privately tracked by the Gridmaster. A Runner can spend any positive amount of Power to increase their Number-Crunches by that amount, though if that runner is in a non-empty cell, this increase is divided by four (rounded down to the nearest integer).

In the rule Running, add a new bullet point to the start of the list of bullet points describing a Tick:

* If the number of runners in the Exit has been at least 1 for the entirety of the last three ticks, and if one of those runners has the highest non-zero Number-Crunches out of all Runners in the Exit, that Runner has achieved victory. (If the Grue achieves victory in this way, the Gridmaster should create a Blogpost to confirm that the Grue has escaped. The Grue’s location should be blanked, and it can never have its location set to a value again, but otherwise its victory is ignored.)

Create a bullet point in the list in the rule Features with the following text:

* Passcoded Egress: If this is exactly the second time that the Passcoded Egress feature is being added to the Grid, set the cells D4, D5, E4 and E5 to have the value of Exit.