LCS Season 4's contract seems to restrict participants from advertising competing games, including Dota 2, Diablo III, and StarCraft.
Videogame tournaments are big businesses these days, especially with vast audiences tuning in for championship livestreams. Being a business, participants are naturally expected to follow certain contractual obligations, usually addressing conduct and other legal matters. What you don't always see are limitations on other games that players are forbidden from streaming. Yet that appears to be the case for League of Legends Championship Series Season 4, as the fine print restricts players from streaming anything from Dota 2 to World of Warcraft.
"The following companies and/or products are not to be advertised during or adjacent to League of Legends content during the term," the contract reads, going on to list games from 21 gaming publishers. Since the section is titled "Sponsorship and Streaming Restricted List", that limits players from publicly playing Dota 2, World of Warcraft, Hearthstone, the Diablo and StarCraft franchises, and more for LCS's duration. Even Zynga's Solstice Arena made the list, as did Ronimo's Awesomenauts and Wargaming's World of Tanks. The contract also forbids the general streaming of content from gambling websites, regardless of title.
The contract states that the restriction doesn't extend to unlisted titles, presumably because they aren't in direct competition with League of Legends. So far, Riot Games and Smite developer Hi-Rez Studios have declined comment. The contract text in question is linked in the image above.