Gerard Van Ginderen's page

@ Mr Charisma:
I am all for giving a perception check to notice there is someone invisible there and even to pin point the square he is (which my PC did in his turn).

I have no problem with the reactive perception check for the PC to detect movement to another square with all the combat penalties etc. Seems fair to say the PC notice movement.

My question really becomes does the PC gain another free perception check to pin point (normally pin pointing happens in PC's turn) where he's moving to. If so, then I guess the PC could Step Up towards the NPC.

Your variant includes the pinpointing which is interesting and worth considering.

Which brings me to

@ Mondragon and @ UnArcaneElection:

I could see that the PC detects movement and can use step up without knowing if he Steps Up in the right direction. But after the step up would the PC need to do another perception to "Pin Point" and is that free/reactive or in the PCs turn?

Your suggestions gives a little credit to the feat and the invisibility spell.

Dear Piazo,
We have reached an in pass and need a little help with rule interpretation.

Situation:
• 1 x PC Character fully visible with Step Up feat having made perception check to pin point an invisible enemy in the 5-foot square next to him.
• 1x NPC Enemy invisible wanting to take a 5-foot step away from the fully visible PC character to cast as spell.

After the PC turn in which he used a minor action (page 186) to make a perception check to perceive pinpoint the NPC and then attacked. The NPC in his turn tries to take a 5-foot step back to cast. The PC wants to use his “Step Up” feat claiming he “pin pointed” with perception so he can follow him.

Perception Pin Pointing means you are aware through your senses which square a create is standing and swing hoping to hit the invisible creature in that square (still 50% miss chance from total concealment). Attacks of Opportunity can be made if the creature sticks around and provokes, or moves beyond 5 foot and then attacks. On that note the PHB2 vs creatures you can’t see; says you could make an OA (at -5 for total concealment) against an invisible creature that hasn't made a stealth check. So this means you can react to invisible creatures say casting next to you.

Isn't it that the PC realizes the NPC has moved until it’s his turn again in which he can try to “perceive pin point” the NPC again. I feel that “Pin Pointing” is not sight (tremor sense, heat vision, etc) and that Step Up can only work if you can see the creature.

I found that the NPC does not provoke an attack of opportunity as he only takes a 5-foot step, and is invisible so can’t he followed with the step up feat. A new perception check in the PCs turn will be needed to re-pin point the creature.

What do you think?