I have a dungeon crawl style game and it has been progressing well.
One of the main mechanics for keeping track of stuff that can happen to player characters or monsters, is the placement of tokens on the card that represents said character/monster. These tokens then tick off at the end of that entity's turn, and their effect happens at that time.
As an example, say Bob has been knocked into the bonfire, and has a burning effect applied. The character is on fire, and gets 2 fire damage tokens. (This will represent damage-over-time as opposed to direct damage that happens all at once.) They are stacked on the character card, and at the end of that character's turn, one of the tokes comes off and does a point of fire damage. The next time that character's turn comes around, the second token will come off at the end doing another point of damage.
This has been a pretty straight forward rule to play with. And it's the same for all effects, whether they are damage, healing, or some other continuous status effect. It's easy to remember and its consistent.
But there is a problem. It mainly comes from applying effects to yourself during your own turn.
And it seems to boil down to a design choice of whether to keep the mechanic consistent, or to make it more intuitive.
Here's another example. Bob the Barbarian decides to spend this turn to use an enrage effect that gives him a bonus to damage on later attacks. His enrage ability says it lasts 3 turns (3 tokens).
Under the consistent version, one of those tokens is going to tick off at the end of this turn. So in reality he is only going to get 2 effective turns worth of enrage that he can attack with. And this is a bit non-intuitive.
The other option, is to stipulate that any effects that get applied during your turn don't tick at the end of that same turn.
So you would actually get 3 turns worth of enrage, but now there is an exception to remember in the rules, which increases complexity.
Which way do you think works better?
Some effects can be placed on yourself, or another ally, or even an opponent. This can create a duration mismatch in situations when the tick would come later for self-buffs.
The problem with ticking the auras at the beginning of the turn, is that it effectively makes them direct damage. The effect is delayed in real time, but not from the target's point of view.
Here's what I mean:
Fred casts a fireball at the 3 health giant bunny. The fireball does 2 fire damage directly and 1 fire damage over time (aura).
Normally this would do 2 fire damage immediately, then the bunny gets a turn, and then dies at the end of his turn due to the aura ticking the final point of damage.
If the aura ticks first, the bunny will die before getting his final turn. And the fireball might as well have just been 3 direct damage all along.
Now we could stipulate that damage during your turn doesn't kill you until the end, but now that's another rule.
Here's the current turn structure:
Every entity gets a turn, and it goes: player, mob, player, mob, etc.
1. Movement
2. Action (An attack is an action, but not all actions are attacks.)
3. End of turn stuff
Some things are instants, and they can be performed at any time including other turns, and there is no limit to the number of instants one can perform, though they usually have some kind of built in limit or a cost.
So timing can get wonky due to the fact that effects have a variety of delivery methods. They may be instants, or actions. And them may be placed on self, ally, or opponents. So there are effectively 5 different timings:
Instant, Self, Own Turn
Instant, Self, Other Turn
Instant, Ally/Opponent
Action, Self, Own Turn
Action, Ally/Opponent, Own Turn
And each one has slightly different implications on the timing of the effect. So this is why it seems necessary to have clean rules regarding timing and duration.
Now, I've been trying to clean up some of the more unusual effects into simpler mechanics, but their problems only seem tangentially related to timing issues.