I should clarify as to what type of dodgeball. The type of dodgeball I like was the first type I learned. My Grade three teacher (Hi, Mrs. Haase!) called it "European Dodgeball". I've played a few other types since then; some were good and some seemed stupid. However, I'll still describe the types I know of.
Since there's not many rules, they can be easily changed as the players see fit (as long as they agree before the game starts!). There's a good list of other types of dodgeball mentioned at the end of this page. This list only has the types of dodgeball I've played.
The game would begin with everyone in the central rectangles, except for one person in each of the C's. (There were about 12 people on each team, in my grade 3 class). The two teams in the center would try to throw the ball at people in the other team's central area. Once you got hit, you were 'out' and would be sent to your team's C-shaped area. However, you would still be part of the game. Once in the C-shaped area, you could throw the ball from your C-area at your opponents in the center, if the ball came into your C. You could not leave the C (ie. you couldn't be made 'out' again and sent somewhere else). Eventually, there would only be one person left in one of the central areas. Now, the opposing team had ten shots. If they could not hit your last player using these ten shots, your team won. If the last person on your team got hit, the other team would win.
There was a small technicality in the way we played. To make the game more fair, the person who started the game in the C would go back to their central area once someone on their team had been hit. This way, nobody had to spend the whole game in the C, but there would still always be someone in each C. If I remember correctly, we also had a rule where if you caught the ball thrown at you, the person who threw it became 'out'. I can't remember for sure if we played that way in grade three, of if I've just borrowed the idea from somewhere else.
The game began with many (I'd say a dozen or so) balls placed along the central line. These were strange balls we used in grade ten. They had sponge on the inside with a thin outer plastic layer over it. There was a small hole in the plastic. If you squeezed the ball, all the air would slowly hiss out. You could then (for example) put the ball down and it would take about ten seconds for the ball to suck the air back in and become its original size. I've never seen that type of ball anywhere else. (I doubt anyone cares about strange balls, though....)
Each team's members laid down on the floor at their side of the gym, behind their line and feet against the wall. When the teacher yelled "Go!", we'd all get up and try to get the balls. If you had a ball, you would throw it at your opponents on the other side of the central line. (I can't remember if you could cross the central line, but I doubt it.) You were 'immune' to being hit if you were behind your own inner line. If you were hit, I think you had to go back to your wall and wait ten seconds before you could go out and start playing again. I don't think anyone became 'out' permanently. I can't remember what caused the game to end, or if there was ever a winner or loser. (Maybe you stayed 'out' after all, or could no longer go past your inner line).
There were two teams of equal size. One formed a circle around the other team. The people forming the circle would try to throw the ball at the people inside the circle. If you were hit, you had to join the people forming the circle. Eventually, everyone in the middle would be 'out'. (Maybe there was a final "ten shots for the last person" aspect to it. I can't remember.)
The gym was split in half, with a team in each half. Several balls were placed along the central line, with the players along the wall at the back of their area. When the game started, everyone would run toward the balls, and we'd try to throw them at the other team. If you were hit, you'd have to sit down where you were hit. You weren't supposed to cross the central line to the other side. Once the ball bounced off the floor, it was 'safe' to be hit by it. We also decided that if you caught the ball after someone threw it (before it bounced), the person who threw it would have to sit down. It usually seemed 'safer' not to try catching it, because if you fumbled and dropped it, you'd have to sit down.
Before the game started, each team would choose a "doctor". This doctor would have to touch ('cure') one of their team's sitting people. After getting up and returning to their team's wall, the player could start playing again. If your doctor was hit, he/she would have to sit down and could not get up again. Once this happened, anyone on your team who is hit will be down perminently. You're almost guaranteed to lose once your doctor's down, since you're slowly losing all your players while the other team still has most of their's. Once everyone on a team is down, the other team wins.
A point of strategy was to have a few players ("doctor's assistants", perhaps?) to stand in front of the doctor to protect the doctor from the other team's throws. This also helps hide who the real doctor is, since you could have several people touch a sitting player at the same time as the doctor.
A variation we were thinking of trying was having more than one doctor. Maybe doctors could 'cure' each other (leading to a long period of time before anyone would win). The alternative is being left with only one doctor.
(We had a variety of ball types, and some were much easier to throw than others. (It was hard to throw light balls long distances.) One was a really big (apporximately) 3-foot wide ball. It was hard to throw, but it was fun to try throwing it anyway. I'm not sure anyone ever got hit with it, despite how hard we tried....)
I found I got a real workout playing dodgeball. There was no time to sit around and relax, even when you were in the C-shaped area (in "European"). Everyone had to run around, pay attention to what was going on, and predict what others might do. In other sports, it seemed (to me) that the 'really cool, tough guys' would always take the important 'forward' positions, and leave the less skilled players 'way out in left field', so to speak. In dodgeball, everyone had equal imporance as the rest. It was a level playing field (no pun intended).
I commented to a friend that it seems unusual that most people I've talked to enjoy dodgeball, yet there's no groups or teams (at least where I live) that organize games. He pointed out something that I hadn't thought of before, but seems true when I think about it. A big aspect of the "fun" of dodgeball may be due to the fact that we don't play it often. I'm sure that if I played dodgeball a few times a week for a months, I'd quickly get tired of it. It would get fairly dull, just running around the gym all the time throwing balls at people. Maybe it's better that dodgeball's not an everyday activity. This way, it becomes much more enjoyable when we do play it.