Question: I'm working on a new board game where there's an action (we'll call it *Brazening*) that only happens every X turns (let's say it happens every 5 turns).

What's a good way to keep track of when it's time for the next *Brazening*?

The perfect method would:

* be easy for players to do
* be hard for players to forget
* require a minimum of pieces or moving parts
* not require pencil and paper

There might not be a perfect method.

Answer: 
Here is a solution for 3 players and more that only needs one object to move and only at
*Brazening! time* so it is unlikely to be forgotten.
I think it meets all your requirements and might blend in your game
without looking too artificial.

In its basic form the number of turns between *Brazening! times* depends
on the number of player which may, or may not be a good feature,
depending on your secret game mechanics.

The idea is that *Brazening!* happens when the player has the Brazen
token during his turn.
The *Brazen token* might be anything but making it substantially big
(such as the totem in Jungle Speed) decrease the likelihood of
forgetting it.
The *Brazen token* is passed from player to player at each *Brazening!
time* in the opposite sens of the change of turn.

The following drawing explains it for four players marked by numbered
circles.
The turn direction is indicated in orange and the *Brazen token* passing
direction is in blue.
The *Brazen token* is figured by the blue 'B' and the turn by the orange
'T'.
The number of the turn is written in orange in the centre square.

![Sequence of turns for four players](https://i.stack.imgur.com/zijeZ.png)

Based on this simple mechanic, you can adjust the number of turn
between *Brazening! times* by altering the passing rule.

If *Brazening!* requires some specific actions to be done, then you can
ask the player having the token to do it so the player doing the *Brazening!* changes every time. It might even been done *with* the object, thus making it blend smoothly with the game theme.
You could try a method similar to the dominion method of keeping track of actions; say it out loud! It *never* fails.

> 
> Say how many you have left out loud; this trick works every time (i.e. "I'm playing the Festival and now have two Actions remaining. I play a Market and have two Actions remaining. I play another Festival and now have three Actions remaining….").
> 
> 
> 

Have your players start their turn with "It has been 1 year since the Brazening" and when they say "It has been 5 years since the Brazening" they have to do the brazening action. Remember: *this trick works every time*

You could add a minor penalty to a player who gets the number wrong to encourage everyone else to pay attention and keep track!