Ventures were in existence from 1968 through the the early 1990s, as part of the Brownie 'eight-point programme'. The Venture badges were given for any pack project which the whole unit was involved in - this could be a challenge, a good turn, a Brownie holiday - any sort of joint enterprise.
Initially the badges had a sticky patch, and numbers could be obtained to stick on to indicate when a Brownie had taken part in a second, third, or more ventures. Later these were dropped, and most units just issued the badge the first time the Brownie was involved in a Venture. The shape of the badges was also changed, and then the colours reversed, before they were dropped with the introduction of the Adventure programme.