What about a contract reward system?

Just hear me out,

By contract, I mean that it describes a certain task or challenge to perform in-game (for example, "achieve a minion score of 200" or "achieve a triple kill"). However, these contracts require IP to purchase, and a maximum number of one contract per day would be in place. The reward for completing these contracts would depend on the difficulty of the challenge, but in any case if a person successfully completes a challenge then whatever buy-in IP they had spent to buy the contract. The rewards for completing a challenge could be anything from IP to RP, key shards to summoner icons, skins to champions etc.

For example: Let's say that I see a list of approximately 10 different contracts of varying degrees of difficulty for me to choose from. I decide to select the contract that costs 250 IP to buy into, the challenge is to "have your team kill the dragon 5 times in one game." The reward for doing so would be to "receive a random champion worth at least 3150 IP" and I have to complete this task within 3 games. If I were to be unsuccessful, I would lose my 250 IP and not be able to select a new contract until the next calendar day. If I were successful, I would not only get my 250 IP back, but I would also receive a champion of at least 3150 IP, but I would still not be able to choose another contract until the next day.

Food for thought I suppose.