How would you roleplay the Arcane Trickster's "tricky spells"

[PuddingSeven]

I'm wondering how you guys would actually handle the AT's Tricky Spells feat. The ability to cast any spell without V, S, or M components is a pretty powerful ability, from a role-playing standpoint.

Tricky Spells:

Spoiler:

Starting at 5th level, an arcane trickster can cast her spells without their somatic or verbal components, as if using the Still Spell and Silent Spell feats. Spells cast using this ability do not increase in spell level or casting time. She can use this ability 3 times per day at 5th level and one additional time per every two levels thereafter, to a maximum of 5 times per day at 9th level. The arcane trickster decides to use this ability at the time of casting.

So, given the ability, and taking into account the overall concept of the Arcane Trickster character, including key words like:

* "...guile and craftiness..."
* "...the subtlest aspects of the arcane ..."
* "...subtle or confounding..."
* "...mischief and thievery..."

and game mechanics like:

*Disable Device 4 ranks minimum
*Escape Artist 4 ranks minimum
*Special: Sneak attack +2d6 minimum
*Ranged Legerdemain (disable device from 30' away)
*Sneak Attack
*Impromptu Sneak Attack

...how would you as a player or as a DM handle a few hypothetical scenarios?

Scenario 1:
The party is facing off against a group of brigands, with the party leader in a verbal confrontation with the leader of the bandits. Picture the meeting with Redfoot at the big bell in The Usual Suspects. The other party members and the bandits are all spaced out on their respective sides, behind the leaders. The AT is probably the least dangerous looking person there. Combat has not started and the players have not yet rolled initiative.

The party's AT wants to cast a tricky spell. Let's say, Mage Armor. Again, no VSM, nothing to indicate the AT is casting, and keeping in mind the concept of the AT...

Would everyone be asked to roll initiative?
Would combat be considered started?
Would the bandits even be given an opportunity to react to the "casting"?
Would the bandits even know he cast a spell?

What if the spell was Web or Fireball (targeted at several of the bandits), how would that change things? Would it be the automatic first action in a surprise round? Would the AT's own party be caught be surprise?

Scenario 2:
The party is sitting at a table in a crowded tavern. The town bully walks in and starts harassing a young lass. The AT uses Tricky Spell to cast Grease under the bully to cause him to fall and humble him a bit (or enrage him, but hey that's Chaotic for ya). Would anyone be able to identify the AT as the source of the spell? If someone was watching him closely, would he look like he was doing anything other than staring into his beer for a few seconds?

I love the concept of the AT as a fun character to role-play (not the best to roll-play, I admit) and I'm curious how others would adjudicate situations like these with a non-VSM spell.

Do you guys see any situations where the Trick Spell ability isn't quite all it's cracked up to be?

[StabbittyDoom]

Technically (By RAW) you always get a check to identify what spell is being cast, even if it has no components.
Also, you are spaced-looking when casting, leaving yourself open (hence the AoO). This is part of what makes it "obvious" you are casting a spell.

My ruling: If it had no components and you cast defensively (to avoid the spaced-out part) you could get away with only those who have detect magic knowing who just did that. Unless of course the spell itself has an effect that comes from you (like magic missile or burning hands), in which case it becomes obvious again.