Using Readied actions and the grease spell for sneak attacks in pathfinder

Question

My group has played 3.5 for quite a bit, and now we are with pathfinder. One of us likes to play rogue,and is used to work in tandem with our wizard to take advantage of grease in order to land some free sneak attacks, and was disappointed that he could not do the same in pathfinder without some other person helping them to move his target to trigger an attack of opportunity.

So he try the following tactic: he ready an action to move adjacent to a enemy in a greased area when he start to move in order to trigger an attack of opportunity due movement. I do not see any problem with that and allow it.

Later, the player reads that you may take a 5 foot step as part of you readied action, and proposes an new tactic: Since he acts after his target, he moves and remain at 5ft of the enemy in the grease area, and ready a 5ft step + attack with the same trigger. When the enemy moves at the next turn, he eats two attacks, the readied attack and the attack of opportunity (as described here). The attack of opportunity is a sneak attack, as before, but the player says that the readied attack is also a sneak attack, since it landed while the enemy was moving, and thus flat-footed due grease effect.

By the rules, a readied action interrupts the action when it is taken, but I'm not entirely sure if in this particular case the enemy has already started moving (and is flat-footed), or he takes the attack before moving, (so he is not flat-footed) and then moves.

At the end, I ruled that the readied attack took the enemy flat-footed and was a sneak attack, both because I like my players using tactics, and because the drawbacks and the work needed to set-up the maneuver were a more than adequate cost for the advantage gained, and I'm fine with that as a house rule, but now I'm curious: There is any rule that explicitly back-up (or refutes) my decision?

Answer 1

The rules do allow such a readied Sneak Attack

The wording of that passage in grease is, in my mind, very unclear, but readied-action attacks and attacks of opportunity are at least two cases that clearly do work. They take place during the movement, so they definitely work. Readied actions basically take place whenever the person who readied the action wants it to, so you can definitely ready an action for “as he moves past me” rather than “right before he starts to move” if you like, and clearly the Rogue would like to.

As you note, this is a really difficult maneuver to use effectively. Worse, as the Rogue levels, there’s very little he can do to improve it; stuff like Two-Weapon Fighting et al., iteratives from extra BAB, and the like, aren’t going to work with it. So as he levels up, instead of getting to improve this tactic with his feats and other choices, all he can hope for is extra Sneak Attack dice – which aren’t going to keep up on their own.

Note, though: “he moves and remain at 5ft of the enemy in the grease area, and ready a 5ft step + attack with the same trigger,” doesn’t quite work: he could only ready that action if he had not moved already in the round. If he was already in position and did not need to move into it, then it would work.

I’d strongly consider reverting to the 3.5 rule

While grease was and still is one of the best possible standard actions you can take, this particular facet of the spell was a good thing, in my opinion. It encourages teamwork and is an excellent example of a Wizard helping his teammates shine, rather than stealing all the spotlight himself. If I was to nerf it, rather than removing this aspect, I’d most likely tone down the spell’s double-jeopardy nature, or its effectiveness even when the enemy saves and makes his check.

This particular rule is thus more of a nerf to Rogues (who, after all, could have easily gotten a wand of grease since as a 1st-level spell it’s fairly cheap, and they have UMD in-class) than it is to Wizards (who still have plenty of options). Rogues don’t need a nerf. In general, Pathfinder makes it decidedly more difficult for Rogues to get multiple Sneak Attacks per turn, and I don’t think that improves the game at all. It was, in fact, already too hard for them to do this in 3.5, in my opinion. So I’d strongly consider reverting to the 3.5 rule.

Answer 2

I'm going to have to rebut the selected answer. Yes, if you attacked a creep that was moving (or starting to move) on grease you would get a sneak attack via the creep being flat footed.

However, you wouldn't be able to take a 5' step in this situation unless you did not move to get into the "5' step position". It's still the player's same turn, and the player can't take a 5' step if they have already moved.

If you were in a situation where you readied an attack based off of movement and were able to take your 5' step (because you didn't move on the turn you readied the attack), then you would be able to step up and get your sneak attack. However, at this point, the creep would be able to change its mind about moving and stay there and attack the now-in-range PC (assuming it was the kind to engage in melee). If it decided to stay and attack, you wouldn't get an Attack of Opportunity based off of movement because you weren't threatening before you stepped up (if you had already been in range then yes, you would get both your readied attack and the AoO), and it hasn't actually moved.