Free-to-Play  

ZAM Network Wikibase™ Dictionary

see also: Pay-to-Win

Free-to-Play (F2P) is also sometimes referred to as Micro-Transactions. The player is free to play the game, and most F2P games are conscientious about keeping all required elements of play free, but conveniences will cost you through an online store.

• City of Steam - This one does have some Pay-to-Win elements but can be played well for free
• Dungeons & Dragons Online
• Everquest II Extended
• Lord of the Rings Online - differences in F2P play
• Runes of Magic - The Cadillac of F2P, RoM has sworn to NEVER allow P2W to creep into the game and has kept that promise since 2009
• Vindictus

We are sure there are many more, as well.