Lawn Jenga: All you need is 6 pieces of 2x4x8 lumber cut into 10.5" pieces. 54 pieces total. Sand the pieces so you don't get any splinters & if you want, you can spray paint the wood or paint the ends in wedding colors.
Giant Jenga - Write books of the Bible on the boards and have kids play Jenga by doing books of the Bible in order. Love Bug Living: DIY Giant Jenga Outdoor Game - Fun party game. Thinking you could use 1x2 also