Made in pre 1.2 for a PvP map called LBE Valentine's Hoedown, which would of been 2 years ago at Valentines 2013. It is quite a rough and large build, could be shortened a lot but I ended up making the newer 2 Team randomiser, this had quite a specific use. From a group of 8 players it will create 4 pairings of players. It is made up of 5 different sections, A-E.
Within section A there are 8 copies of this mini system. The mini system includes 3 door randomisers, one at the top and one either side beneath it. The top one randomly activates one of the other two, which both have 2 random outputs, creating 4 total random outputs. Each of the 4 boulders at the bottom right is connected to an output, so one of them will fall and go into section B. Also each of the 4 outputs is connected to section C, choosing one of the 4 teams for the related playing. There are 4 groups of 2 people, so within the 8 mini systems each team output must be activated twice. When a team has been activated twice, sand will fall forcing the doors to open one way, so the randomiser will be forced to give a certain output, making sure each team has 2 players.
The bottom left randomiser will always choose between 2 teams, say Team 1 and Team 2, as will the right randomiser will choose between Team 3 and Team 4. When either both Team 1 and Team 2 or both Team 3 and Team 4 are full, then the top randomiser will be forced to give an output to the randomiser where there are still spaces left in the teams. So if the bottom left randomiser chooses between Team 1 and Team 2 and both of those teams are full, the top randomiser will be forced to give an output to the right randomiser.
Before the boulder hits the sand forcing a doors direction, the sand will fall again, using dart raps to break the cobweb holding the sand up. If you look at the entire system one of the mini-systems in A is smaller, which is the first one activated and doesn't need the sand as no teams will be full. Unnecessary but I made that one first and expanded it afterwards.
Here is the top of section B, which deals with deciding which sand falls down in the mini systems from section A. It is made up of lots of rows, of which there are 2 types. The bottom 4 rows in this picture are the first type, where a boulder will go through one of them. The boulder is random, coming from one of the 4 random outputs from section A, so each of the 4 will correspond to one of the 4 teams. Each row includes two pressure plates the boulder will activate, each plate connected to a counter which can be seen at the top. There are 4 counters that count to 2, each one connected to one of the 4 rows and corresponds to one of the 4 teams. Once a 2 long counter is completed, it will block any more of the same team outputs, so each one will be completed by the end as there are 8 sets of these types of rows.
The top 6 rows are of the second type. The second type of row has a boulder in the middle, which is activated when a counter is completed. A boulder will go on to activate the the sand falling in each of the mini systems in section A, forcing the doors to open in a certain way. There are 7 sets of these rows, one for each mini system except the first which doesn't need them. There are also 2 longer counters at the top, which will activate the sand in the top randomiser of the mini systems, so it activates when a set of 2 teams is full. One of the pressure plates in the first type of row will indicate which counter needs activating.
Section C is the spawn of the map where the players will be. There are 2 active stone blocks on the side near the boulder at the left, activated by placing a switch on them and pressing it. The bottom one activates the boulder and starts the system, the top on makes players fall down. Each player can fall onto one of 4 of the activate stone block pairs, each one indicating a team. For each player one of them will be randomly activated from the output from section A. I used the TShock warp plate plugin so you will get warped to a different team area, without using the mod I expect you could still make it work so players go to different areas depending on the team, easily now in 1.2 with teleporters.
Section D and E have very simple parts.. D is a simple time delay so everything is activated in the right order at the right time. E is a wire extender, as wires could only go a small distance before they will stop working. Here is the time delay.
Here is the wire extender.
This quite a large build and could of been made much more efficient in 1.1, especially by doing the time delays more precisely, but I started working on different maps.