FASA Games, Inc.

lets suppose a character is exploring a dungeon for treasures, and is headed in the direction of a hidden blade trap with detection difficulty of 7 (page 110 DMG).

what difference makes if the character is actively searchig for traps (moving much more slowly) or just walking with the usual dungeon-crawling carefullness, or just walking in terms of detection difficulty and used talent/skill? Is it detect traps versus DN7 in both cases?

The Detection DN is for making a reasonable effort to look for traps (for example, Detect Trap is a Standard Action, and represents such an effort). In other scenarios, you're supposed to adjust the DN per general rules (p. 89-91 GM Guide), which usually means requiring another Result Level (you actually determine a new DN based off of the Result Level chart and that is your new DN for an Average Result, but under almost all circumstances, you can just go with the higher Result Level from the start).
For example, if your group doesn't spend time looking for traps (and that means no Detect Traps talent or skill, because that's Standard Action, and spending the Standard Action means looking around) but you still think they might spot something, you might require a PER Test with an Excellent Result against 7 (in other words, the DN becomes 15). If one of them has the supernatural ability to smell rusted metal and the blade trap is rusty, he might require a Good Result against 7 only (DN 11 for him). If one of them is drunk, that one might need an Extraordinary Result (DN 19).

I can't say how much of a difference you make between "looking for traps while you walk" and "advancing carefully because it's a dungeon", in any case... ^^

For some reason I never used a lot of traps - never had any thief players, for one thing. Next time I get to run a game, I'm just going to let a few traps spring on the group so that they know to look. But I like the idea of the players poking things with sticks to see if they blow up rather than just rolling the dice. Yes, I've been flirting with old-school dnd resources. So I'm not sure how to strike the balance.

Warning

<Rant mode enabled>

When I think of D&D I think of traps. It invokes memories of generic dungeons without purpose that existed only to be filled with traps designed to kill the player’s fun and maybe their character as well. To strike a balance some of this blame should be apportioned to GMs that lacked any imagination.

In a decent adventure a trap should be more than just a device to protect some treasure. Traps SHOULD be challenging, but should also be part of the overall atmosphere, not just there because the GM has cool idea for a trap.

</Rant mode disabled>

In Earthdawn traps add to the atmosphere when exploring kaers. Have the characters find or stumble across spent traps, sprung by some unsuspecting Horror or even previous explorers. In my last three adventures the player have discovered several spent traps, but in the next adventure, for a change there is a trap that never got sprung surrounded by traps that did. Just knowing there may be more traps in the kaer adds to the atmosphere.

Over doing traps bogs the game down as player characters spent hours searching every inch of a tunnel or room and it can often make the players resentful when every step of the way could be their last and there is often nothing they can do about it. One of the things I love about Earthdawn is the traps can have good reason to be there. Many traps are designed to kill large Horrors so may not even go off unless the player characters do something a bit mad. GM (after a successful Perception Test) “your footsteps make a hollow echo as you walk across this section of the floor” Player “ohh if I jump harder on the floor do I get a louder echo? Hey guys I think the floor is hollowwwwwwwwwww” Sickening crunch.

Traps can be part of the overall challenge or adventure goal. At the start of the adventure have the player characters discover a live trap in the kaer. They can quite literally stumble over it and realise they are not large enough to set it off. Later they discover a Horror has made its way into the kaer. It is large and powerful and they don’t understand why the Horror didn’t spring the trap. Then they realise the Horror was smaller when it breached the kaer and continues to grow as it eats foolish explorers. To kill the Horror they must lure it into the very trap designed to stop it entering the kaer in the first place.

Spent traps are a good way to add things to a game you want your player characters to have to help them toward their goals. For example many gamemasters like the player characters to find a healing potion they may not normally be able to afford at low circles, especially if the game is combat heavy or if some of the player characters have low Death Ratings. A spent trap with a dead explorer is a perfect game mechanism for finding various gear items an explorer would carry. This is much more in the spirit of exploration than being handed an expensive potion by someone the player characters barely knows because their coming was prophesised.

Thieves are handy when traps abound, however the adventure should not grind to a halt because there is no thief. On a lot of occasions the trap should have the ability to be avoided if it can be detected.

That's some good info. The great big horror traps is a cool concept. When I've read about kaers that had pit traps that did 10 steps or so of damage it's always made me go "hrm, really?"

I have kind of a weird rpg history, because I never actually played DnD. I played badly mangled versions of Gamma World and Marvel Comics RPG, and then I discovered Earthdawn. Other than some homebrews, that's all I've played. I've never really explored a lot of the classic DnD tropes.

in my games i never had a player play a thief pass 3rd circle in pass edition needed to be 5th for the trap talents and haven't had one yet in 3rd edition.
but i use traps in any kear they explore some are sprung some are not. of course the point man always find them just the not the way he wants to.

actually, Thieves and Scouts can make Half-Magic Perception Tests to detect traps and secret doors.

so despite not getting it as a full talent, Thieves can use half-magic for using it until Second Circle, and it helps out Scouts who may not wish to take Detect Trap as a talent option.