My wife and I enjoy playing the trivia games onboard whenever we cruise. We also play trivia once or twice a week when we go out to eat .We usually find some teammates on the first day of the cruise so that we have 6 people playing. We have found it helps to have some people from the North America as well as overseas so we can have a better shot at the questions. Unfortunately we have seen several examples of cheating, including: 1) use of phones and tablets, 2) reference sheets (both notebooks of old quizzes as well as sheets with notes for topic specific trivia games, 3) changing wrong answers after being graded to correct answers and rescoring their paper, 4) using teams big enough to make up two or three teams, 5) grading their own papers, or 6) just lie about their scores always being 1 higher than the 2nd place team. Most of the cruise director's staff doing trivia anymore make announcements about the team size and not to use electronic devices, but the other methods still seem to occur. I think the Q/A notebooks should be explicitly banned at trivia and if seen looking at them your score doesn't count.
Worst example of trivia we have seen was a couple of years ago. We passed our paper to another team to score it. Before they handed their paper over, they had a person at the far end of their table copy answers off of our paper to fill in blanks on their answer sheet. We went and grabbed our answer sheet back and told them we saw them cheating. Fortunately they had some other wrong answers and did not win, but that is very brazen to cheat like that.
Some of the people hosting trivia have done it enough that they have a large collection of questions to use and do make an effort to not repeat trivias while repeat passengers are on board. On our last cruise we had music trivia every evening, which does seem to frustrate the cheaters and people who have heard the questions before. A couple of trivia hosts have told us they have enough trivia questions to get thru about 4 weeks of cruises without repeating a session. Newer crew members have not had a chance to build up their collection of trivia questions - it might be nice for Princess to provide more questions for the crews, but some of the people we have competed against would probably still try to get hold of all of these for their Q/A books to use. We have even seen some very knowledgeable passengers put together trivia contests and fill in as the trivia host. Their team would not compete during these sessions - they did this because they wanted to make the trivia more competitive. Teams playing certainly had never seen any of these questions before!
Are the prizes worth the effort some people put into cheating? No, of course not. Some of the prizes we have used at home, but there are only so many water bottles or plastic clips you need at home or for friends/family. We also enjoyed the old prizes such as the reversible Princess tote mentioned earlier and the Princess caps that we never see offered anymore.
Teams and individual players do score perfect scores playing trivia and we are glad for them. They may know the particular topic of the trivia session. We saw a country music disc jockey win the country music trivia with a perfect score once; did we think he cheated? No, he just had a large knowledge base to draw on in his head. He certainly didn't know what songs would be played.
Do some hosts have incorrect answers? Yes. Do they have time to correct it during the short time set aside for the trivia? No. What we do when they have an incorrect answer is to wait until after prizes are awarded and then tell them about the error - they are more receptive when not being shown up in front of the crowd and they usually do want to get it right. Asking questions dealing with a country you do not live in is difficult and they rely on the internet which, believe it or not, does have errors posted on it. Plus with the ship's internet, it can be a very slow process to look up trivia online.
As far as people leaving prizes for the crew as tips instead of leaving money, we have seen that mentioned before on cruise critic. We have never seen it personally, but we have certainly heard the rumors of certain couples.