TORONTO -- It starts innocently as a time-filler on a bus or a stress-buster after a hard day at the office.
But as the shiny gems of Bejeweled Blitz or Candy Crush's brightly coloured bonbons burst in a satisfying cascade of explosions, you may find your playing takes a more compulsive tone.
A few minutes may turn into an hour and you still haven't loaded the dishwasher, picked up the book you are reading or engaged in a conversation with your partner or kids.
The fact is, some of these games can really hook users, experts say. And though for many people there may be a net gain to playing, you may want to keep an eye on how much time you are devoting to them and what it's costing you in terms of what you aren't doing as a consequence and sometimes even what you pay to play.
"It's not a problem unless it's causing problems," says Dr. Bruce Ballon, a psychiatrist who developed the gambling, gaming and Internet-use clinic at Toronto's Centre for Addiction and Mental Health.
"But some people forget it is actually causing problems, such as, 'Oh, I'm not hanging out with my family as much anymore,' or 'My kids are getting angry about it,' or 'I'm playing these games in the middle of dinner.' "
Ballon created his clinic because he recognized the similarities between Internet and video games and gambling. "There are huge parallels," he says, suggesting the visual and audio cues as well as hidden costs built into some games are much like online gambling.
"It's inherently reinforcing," Susan Whitbourne, a psychologist who studies casual video-game playing, says of this type of entertainment.
"They know what they're doing when they make these things. They're designed to be engaging and exciting and pretty."
Whitbourne and Ballon insist these games have good qualities as stress relievers (Ballon) and potentially as cognitive-training tools for older adults (Whitbourne).
For example, Whitbourne says the need to constantly scan an evolving field of play and respond rapidly to those changes mirrors the skills drivers need. Practising them by playing these types of games may slow the decline of driving skills in older adults, she and others hope.
Whitbourne, who teaches at the University of Massachusetts Amherst, wasn't looking into the addictive aspects of Bejeweled Blitz when she started the study, though her personal experience perhaps might have led her there.
She was introduced to the game by a student and remembers thinking: "Wow, this is really making me respond a lot more quickly than I feel comfortable doing. I wonder what that's about?"
Whitbourne and Ballon have some suggestions for people who want to cut back on their game-playing, though he cautions there isn't a simple fix.
The first thing is to get a good handle on how much time you are spending on the game, when you play it and what you are sacrificing by devoting time to it rather than to relationships or other endeavours.
Ballon suggests you try to figure out why you are playing. "Why am I doing this? You have to develop the self-reflective skills to try to combat that."
Set limits on playing time and be strict about them, says Whitbourne. Don't fall into the "one more game" trap. She suggests finding a way to reward yourself for stopping once you've reached the time limit you set for a session.
Whitbourne also suggests people play free versions of the games, or ones that can be played after a one-time purchase cost. "Don't be paying for boosters, because you will get sucked into a hopeless morass."
Another approach is to simply not turn on the device on which you play the game, Ballon says. If your problem is making yourself stop when you decide to play a little before heading to bed, don't even start.
In fact, that approach may be advisable for people who have trouble controlling their game-playing when the new game comes down the virtual pipeline, Whitbourne says.