To make a valid post in this game, you may:
1) Post an interesting fact related to the number of bells/weed you claim (according to Tumbleweed rules).
2) Alternatively, you may post an interesting fact about bells or tumbleweeds.
3) Alternatively, you may claim a number of bells or weed exactly one more than the number claimed in the last claim, be it bells or weed.
4) You may as an alternative move post a picture of a bell or a picture of a tumbleweed or a picture related to one of the interesting facts mentioned before.
1) 18 bells - 18 is the legal age for drinking in the UK
2) The tumbleweed is found in the desert
3) 19 bells (if the last claim was 18)
5) If an invalid claim is made, the clock is reset to zero and the number of bells and/or weed claimed resets to zero.
6) Consecutive posts are banned when posting according to rules 1 and 3, but you may post consecutively according to 2 and 4.
The earliest evidence of the use of bells comes from the 3rd millenium BC, in Ancient China.