A lot of games recruit members with a promise of a posting frequency requirement. Mine is 2 days. I will be enforcing this pretty strictly. Unless you let us know that you won't have access to a computer or will be on vacation, etc, then I will do one of two things:

In combat I will assume that your character automatically fumbled or had some other reason for having no action in the round of combat and NPC them accordingly.

In RP situations, I will generally ignore your character but if there are things that your character needs to participate in, I will NPC them accordingly and during that time they will not be able to roll any saving throws, skill checks, etc.

If it becomes a trend that you don't post at least once every 2 days, I will notify you of the problem. If it still isn't fixed, I will either kill off your character or find a reason that they need to leave the party and remove you from the game. I know it sounds strict but I've had too many games fail because of having to wait on one or two people who can't find the time to put into a rapidly moving campaign. But all in all you technically have 2 warnings so I hope it doesn't come to that.