Roblox previously offered this as a free currency you earnt upon logging in daily. Every time you visited a game, the developer received 1 TIX. Additionally, Roblox had a feature called RoblEX where Robux would equate to a certain amount of TIX, generally between 10-20 TIX = 1 Robux and vice versa. Players could use TIX to buy in-game items or avatar accessories.
Roblox removed the feature because of "confusion" and "delay" for new users; albeit, David Baszucki also stated that the primary reasons were: "product simplicity, botting [people who abused the daily login reward with bot farms], and not incentivizing certain behaviors."
Roblox announced the removal of TIX on March 15th, 2016. They honored the removal with Tixapalooza, where users could: - buy items with the TIX decal in exchange for their remaining TIX, with one new item coming out daily until April 13th; or - exchange their remaining TIX into Robux.
On April 14th, 2016, Roblox officially removed TIX from the platform. Any unspent TIX were erased. TIX brief and last reappearance was in The Classic Roblox event in 2024.