Hi all,

What is the best way to program a time limit for a demo game? For instance, I would like to place a 60 minute time limit or the program expires after so many days. How should I go about doing this?

thanks.

60-min time limit:

static DWORD startTime=timeGetTime();
if (timeGetTime()-startTime>60*60*1000) _exit(0);

(though you just *might* want a bit more graceful exit)

Expires after a number of days:
When program starts, check if a specific registry key exists
if it does not, create it and write todays date to it
if it does, read the date stored in it, and if the diff with todays date is too big, the trial have expired.

When tracking days...make sure you also track the last date of use. Then you can check to make sure that the current date on startup is not *less* than the last date of use. That way, if the user sets their clock forward to thwart the trial period, you can detect it and just end the trial immediately (or adjust it).

-David

thank you for the replies.

I was wondering how does Real.com or the PopCap time limit their games. Also, is there a (cheap) tool out there that does this?

thanks, again.

On a related note, and this being my humble opnion.. I am very skeptic about the benefit of time-limiting a demo.

This is probably just me, but I feel very irritated at the idea of not being allowed to try the demo at my leisure. Perhaps I need to stop mid-way through the trial due to some urgent errand or something and end up not having enough time to try the demo.

Also, I feel it shows a lack of goodwill from the part of the seller. After all, it costs nothing to let your potential customer play the demo indefinitely, the bandwidth cost was expended on downloading the demo anyway. This would be in contrast to a traditional try-before-you-buy scheme for physical products, where the product is on "loan" or the seller is spending time with a potential customer. Actually, the potential customer might even be tempted to re-download the demo in the hope of extending the time limit i.e. wasted bandwidth -> wasted money.

I think it also gives a sense that the game is so good that the potential customer only deserves to try out the demo (which is level-limited anyway) for a limited period of time. I wouldn't expect that sort of attitude for the demo of Doom 3, let alone a smaller-scale indie game.

My reaction to a timed demo is usually to try it once for, say, 5 minutes, exit, and uninstall, keeping in mind that somewhere in my Windows registry there's a key-value that's sitting there for nothing.

As I said, this is my own view of course, but I think that many potential customers share one or more of these feelings and may be disinclined from actually purchasing because of this.

I firmly believe that it is better to tempt the customer to purchase the game in order to see more levels, more features, the rest of the plot etc. In the meantime, let him / her play the demo at his/her leisure. I think that this is in the spirit of shareware and is an act of goodwill (or marketing scheme!) much on the lines of a 30/60 day money back guarantee.

P.S. Perhaps this post is more appropriate in the Business section, but this thread prompted me to share my opinion :)

I've done experiments using timed vs non-timed demos. For Space Taxi 2 an untimed demo sold about 3x as many copies as a timed demo.

However - That being said, I know of other games that sell about 5x as many copies with a timed demo.

So in the end it really comes down to the particular game or how the untimed demo is limited.

Since there are multiple possibilities for limiting an untimed demo, a simple test of timed vs untimed isn't a perfect comparison, and may not be optimal because the untimed demo could easily not be the best untimed demo. For instance you may decide to limit the untimed demo to the first 5 levels. But who's to say that 20 levels wouldnt sell twice as well for some reason? Maybe it turns out that 5 levels is not enough to hook the player.

At the end of the day though I think you need to test this on a per game basis and see what works for your specific game. If anyone is automatically defaulting to a simple 1hr timeout for all their titles I think there's a good chance they're losing sales.

I can see the reasoning for a system like realarcade where you want some consistency in the sales interface your customers experience and you want to use the best average method, but for most of us it's probably worth testing this.

I have to admit that yours is a much more objective view, at least in terms of the effective conversion rate. Ultimately it's all about finding out what sells best on an individual game basis.

Still, since I feel so turned off by the idea of timed demos I was wondering what's the percentage of potential customers that feel the same way.

Well I just played a timed demo that had an hour of play, and I went through all the content in the timed demo in less than 15 minutes. I'm not sure, but I don't think the time limit is going to be an effective tool in getting me to buy the game.

If the game isn't compelling enough to make you want to play for more than the hour they give you, it's not worth buying. Simple as that...

I switched from a 15 day trial to a 60 minute trial on one of my games and sales increased about 4 times almost instantly. Depends on the game I suppose. I figure if the big boys all do it that way it's good enough for me!

BTW...Real keeps track of the number of milliseconds the game has been played. You can find in the registry a value like 2909256. They also throw in about 20 bogus values so if you're trying to hack the registry you're not sure which one is the real one. Just use GetTickCount when your program starts, store that value and do another GetTickCount when the program ends. Do the math and update your registry value.

I switched from a 15 day trial to a 60 minute trial on one of my games and sales increased about 4 times almost instantly.

Timed seems to work better for more casual games that have repetitive or similar gameplay. Things like collapse, big money, mahjongg etc...