Does a creature know the precise rule effects of a zone or aura when they are affected by it?

Question

My question here revolves around when and how much information does a player or creature gain about an aura or zone, once they are affected by it.

Do those affected know exactly what effects are applied to them in game terms?

Other than by a knowledge check or having a companion affected by it, can a player learn the game term effects of a zone or aura before they are affected by it?

Or do you hide the precise terms of a aura or zone if possible from the players?

Answer 1

Once you are affected by an aura (or any other effect) you should know what happens when you are in it. Whether your character knows that in precise game mechanical terms your players should know. How they choose to reflect that knowledge in their PCs depends on the level or realism in your game.

(some characters know they just lost 5 hp, some PCs may just know they got hurt).

From PHB1 p 57

Whenever you affect a creature with a power, that creature knows exactly what you've done to it and what conditions you've imposed.

You might hide things like (using knowledge checks as an avenue to reveal them, or reveal them as the effects take place)

• If there is a way to stop the aura
• Secondary effects that aren't immediate
• Other effects that fail to affect the current PC.

It's a bit underhanded to not tell PCs exactly how they are being effected unless it is serving a higher narrative purpose that is revealed fairly quickly.