This is a team-based co-operative challenge. The team/patrol must solve the puzzle within the time period. It was designed as one zone within an indoor crystal maze night but can be equally done as a stand-alone activity.
1 fake "bomb" - this can be simply some tubes or a box with wires protruding from it. It doesn't need to tick or have any circuits. I've uploaded a photo of ours (just made from bottles and card). The important part is that it has six wires they can pull out individually as required.
1 set of rules
There are computer games like this (and an activity on here which lists one) but I did it this way because we needed something with minimum expense and setup and also to give a physical object to the teams.
The team are presented with the "bomb" and 1 set of rules (see uploaded file)
The team must defuse the bomb by obeying the rules to decide which wires to pull and in which order.
They have a limited time to do this (suggest 3 minutes)
If they pull the wrong wire - "boom"
If they run out of time - "boom"
If they pull the wires in the wrong order - "boom"