Ah, I think the instructions may be a bit unclear. The important rules are that
an activity must be carried out every 30 minutes, and
chickening out does not count as an activity. Thus, when you chicken out of a roll that was for a scheduled activity, you are required to add 30 minutes to your time until release and then you're immediately back to square one with having to use the table.
Given the above, in the event that a 3 is rolled, the player will be presented with a choice:
1. Accept the roll, which would add 45 minutes and not require them to do another activity right away (since the addition of the 45 minutes counts as an activity).
2. Chicken out, adding 30 minutes and requiring them to perform some other activity right away.
When simplified, if we consider that 30 minutes = 1 activity, then we can see that option 2 above (chickening out) results in 2 activities, while option 1 (accepting) only results in 1.5. This means that, based on the amount of time the player has left, they may or may not be adding 2 additional activities to their dare by choosing to accept, whereas they will
always be adding 2 activities if they chicken out. This is balanced by the fact that, by choosing option 1, they will be forced to keep their diaper on longer overall, which is a penalty in of itself.
I hope that makes sense, and I'll readily admit that it's a bit confusing as it's currently written. I'll have a look at revising some of the wording to stress the important points more clearly. Thanks for pointing out that issue!