Depends on the event. For more events (unless I am camping on the list field) I set up my 9x9 top without the walls. This is just big enough that I can have space for my little household of three and a couple of guests, along with a table for hospitality, a chest or two, my banner(s) and a couple of chairs and benches.
This is the set up that I use for Crown Tournies after I sat in a tent that was "for me" and it became a major social gather. Ladies came and sat in my chair, and I wasn't about to be rude and oust them (esp. since it wasn't my tent) so I had to sit out in the sun in order to watch the other rounds. Course, one time I was driven out of my 9x9 when a troop of ladies in hoop skirts flocked there, but that is a different story.
This same thing happened to my knight one time at a crown that he fought in (and won) when I set up a 30x40 tent that 1/3 of the tent was suppose to be for him. A lady came along with her newborn baby and plopped right down in his spot. Of course, he wasn't going to oust a baby and so he spent the rest of the tourney, kneeling and leaning against the listpost. Problem was that it was around 85-90 Degrees that day and he never took his chainmail coif off, and afterwards he damn near collasped with Heat Exhaustion. We had to get him back to my place before court to get a shower and cool off in the A/C so that he could get his core temperture down engough to sit in court and feast.
For events where I am going to be camping on the list field I set up the 20' Round Pinwheel of Death. I have a divider wall across the middle of it so that our sleeping quarter are in the back half and our entertaining area is the front (this is what we do at Pennsic too). We set up a couple of small tables, some benches, boxes and chairs. The floor is covered with painted floor cloth that we made that covers the footprint of the tent. We hang a couple of banners and painted tapestries and it looks pretty good. Nothing modern on the outside if we can help it. I stopped setting this up at day events after I got down with being more tired from setting up and breaking down the tent than fighting!
I recently bought a A-Frame that I intend on setting up like i've seen some bell wedges recently, open up and elevated on one side for tournies.
In the 12c, according to Holmes, 'Lodges' were set around the areas were tournies were held, I would assume in the safety recesses. These were just four posts that were drove in the ground, and fabric was streched across the tops for tourney day. Here ladies and knights would sit on low stools or pillows on the ground, which would have rushes strew about.
Interstingly, the Lodges were also set up at intervals along the sides of major roads for travelers to crash in for the night.
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