Skill Sets in the Dragon Quest Monsters: Joker series, and Dragon Quest Monsters: Terry's Wonderland are magic and abilities in a skill set with each monster. Monsters you defeat in battle, you will gain exp, but after leveling up a few levels or so, your monsters get skill points to spend. Some skill sets can only be obtained by mastering said skills and synthing your monster that has those skills sets with another monster for that skill set to appear.