Just as I welcomed my students' creativity to create their own character, I hammered on that idea. A couple days ago, I wanted to get students to familiarize themselves with identifying sentences which are not relevant to the main idea. I told them that I would give them a challenge. They got excited and they perked up. I told them that I would say four sentences and they would have to guess which one is not related to the other. As soon as I told them what the "challenge" was, they almost immediately lost their excitement. So, I changed tactics.
"Ok. Here's the deal. I want to make this fun for all of you. You know what I want to accomplish. I want you to identify sentences that are not related to the main idea. If you can tell me how we can make a game which requires us to do that, then I'll do it."
I received a few ideas from the students. A couple were promising. When one of the ideas was expressed, I saw that a lot of students were into it, so I went with that idea. The idea was that everyone will stand up, one student will make up four sentences and will say those sentences twice. Upon saying those sentences for the second time, everyone will duck under the table as soon as the irrelevant sentence is expressed. The first person to duck under the table wins and then they get to be next to make up four sentences. It was a great idea. We ended up playing the game like 6 or 7 times. And, I got students to participate that don't normally willingly participate. After the 7th time, my students got bored, so we stopped playing. That's fine. That was good mileage to me.
So, if students want the lesson to be fun, tell them what you want to accomplish and let them come up with the ideas. Pick the idea which you find to be most suitable for your academic goal. So far, its my view that that is the most efficient way to make fun lessons and hence maximize voluntary participation.
On a side note, one thing I would've changed is to not have students duck underneath the table. Certain students bumped their heads consistently on their way down. Luckily, they were only in minor pain.