A balloon debate is a classic speaking activity that can be adapted in many ways. The original version is based on the idea that there are a number of people in a hot-air balloon which is losing height and will crash killing all the passengers unless the load is lightened by someone jumping out.
The people may be heroes and celebrities, in which case you should choose ones that the students will know something about, or let them choose for themselves. All their contributions to humanity will perish with them if they aren’t chosen to survive.
Alternatively, they can be ordinary people for whom you write profiles including their age, occupation, marital status and indications of their value to society. For example, one person could be a mother of two young children who is also a talented artist, while another is a wealthy seventy-year-old philanthropist.
Students each prepare a short speech taking on the role of the person they selected, in order to persuade the group that they should be saved. After preparing their speeches, they can split into groups of four to give their speeches, then each group votes on which of the four people must jump.
Each student usually takes on the role of one individual, but you could have all the students together debate their relative merits before reaching a group consensus. This can also be extended into a pyramid discussion, where small groups combine into successively larger groups and have to try to convince each other of their decisions.