gam* finds game, gaming, gamification, etc.
Another way, besides placing OR between search terms, to increase the number of search results is to use a truncation symbol. This will find all words that have the same root or trunk. It will find you more results that just searching for the root word.
Databases use many different symbols for truncation, so remember to check the search tips. Most databases, such as those from EbscoHost and ProQuest, use the * (asterisk).