原文有點長 吃掉
關於職業與半職業選手不能參賽以及跟RIOT有什麼關係
相關的東西是這樣的
【第十屆世界電子競技錦標賽台灣代表隊各項目選拔賽報名】《英雄聯盟》
LMS 與 ECS 現役選手不得報名參加（包含各隊伍登錄之候補選手，以登錄名單為標準）。
來源：http://www.esports.com.tw/edcontent_d.php?lang=tw&tb=2&cid=39&id=3593
Swiss IeSF Qualifier 2018 Terms and Conditions for Participation
（台灣的沒找到但找到瑞士的，應該是差不多）
5. Game specific Conditions
b. Non-Eligible League of Legends Players
Due to the license agreement between Riot Games and the IeSF, players who are
featured in the current LCS season or LOL Semi-Pro Events 2017, such as
Challenger Series, are not eligible to participate in the qualifier.
來源：https://goo.gl/FWnPyo
IESF 粉專 2016 年的貼文
League of Legends was previously the official title for the 7th e-Sports
World Championship Seoul 2015. IeSF and Riot Games agreed to limit
participating players to amateur players, who have not participated in LCS or
LOL Semi Pro events in 2016 in order to expand LOL amateur base world-wide.
來源：https://goo.gl/aiFq9a