So many good replies in this thread. Thanks!

In my RPG, the player venture out into a forest to adventure. Sometimes he will come across a emerald fruit that glows gently. If he eats it, it heals his wounds and it will say something like "Your wounds are miraculously healed!". Due to the perma-death, the player will be reluctant to try unknown things or be tempted to Google about it. To avoid these, the description of the fruits will include something like "Based on what you know, this fruit is safe to eat and has a beneficial effect on injuries." After eating it for the first time, the player unlocks a journal entry about the fruit.

What do you guys think of this implementation?

In Ultima IV, I found that the colored potions which didn't advertise their use was on the frustrating side

mystery potions and such are yet another minigame - in this case roulette, or perhaps Russian roulette. <g>.

"take a turn at the wheel! see what happens! you might get a million gold pieces! or it might turn you into a Newt! (hopefully you'll get better)" <g>.

i wanted to say something about it realy depending on your audience, though i guess acharis already made that clear.,

Some games have a design which the player is expected to 'learn' at various points and likely have somethging sprung on them which normally is fatal - requiring restarting now having to get back to that point and now 'Know' what to do or be ready for that.

Coin operated games were like this for a reason, they really were limited in all the games assest/levels so had to do alot of reuse to stretch the game) it was just sheer stubborness to get thru - little skill at all once you 'learn' where the hazzards are.and EXACTLY what to do

One hope to not have a game that way and allow a lttle more maneuvering and creativity in handling a situation - you might still be killed but maybe much less frequently. Discovering what tools can be used (to employ in many ways preferably) and what all they might be used for (the more you find out the more useful they become to solve things)

Of course that requires a better simulation where things happen/behave/react /interact as expected (ie- thing can catch fire -wood easy, metal much harder) one it has been revealed (' what does the gem of mystery do ?? if it was a screwdriver you would have a clue, but if the player is given opportunity to experiment with it and preferably not use up its "one charge " rendering it useless (unless that is the point some few things are supposed to be 'nothing else worked so this must be it' type usage

If it can kill the players character or harm it in a significant way then it should be transparent. Otherwise it can be fun with some hidden elements as it adds to the exploration aspect.