Tactical Movement: Cover, Concealment and Stealth Vs. Perception

For the upcoming adventure I wanted to go over in more detail the rules regarding using Stealth. There will be situations when you will want to sneak up on your target to spring a surprise attack or just to simply sneak by. Basically the use of stealth is skill check that the person’s stealth check versus the opposing target’s perception check. In all most all cases, the person hiding, must have cover or concealment. We will go over the rules regarding both. There are a few rare exceptions to this rule and I will go over those. In addition, I will outline the rules on perception as a skill and also fighting a target you can not see.

Cover: Player Handbook page 280-281
In short, cover is what we have when we shoot from around a corner, or when we hide behind a low wall. We are using the corner, tree, wagon or what ever you hide behind as a shield, making more difficult for the enemy to attack us.
In game terms that means if the attacker selected its’ best corner, it will still have at least one obstructed path to the corners the target occupies. If the target has cover, the attacker takes -2 to attack roles. This can be raised to -5 if the target is using “superior cover” like a window, or arrow slit. Another note about cover, is that it grants you partial concealment (unless you were hiding behind something translucent)

Concealment: Player Handbook page 280-281
Concealment is what we have when we are totally obscured from our enemy. For example, hiding in a room with total darkness, or hiding in or behind a smoke cloud. One of the things important to not about concealment is that, it does not provide and cover. Targets with in area of effect spells, are effected as normal.

Game rules
Concealment: -2 Penalty to attacks
Lightly Obscured - Fog, smoke, Heavy falling snow, heavy rain, foliage
Heavily Obscured, adjacent to attacker - Heavy fog, Heavy foliage, heavy smoke

Total Concealment: -5 Penalty to attacks
Heavily Obscured, not adjacent to attacker - Heavy fog, Heavy foliage, heavy smoke

Total Obscured or invisible
-you do not provoke attack of opportunity
-you have the combat advantage


Stealth
Stealth is a Skill, out lined in page 188 of the Player Handbook and refined in the Player Handbook 2. It is a Dexterity based skill, that is opposed to the skill Perception. Lets talk about basics in how Stealth works in D&D. Stealth is how an action is performed, so no move or standards action is used to become sheathed.


Step 1-the player announces that he will do an action using “Stealth”
Step 2 - the player roles 1d20 for his stealth check at the end of that action. This role will remain his stealth
check for the remainder of his next turn. Modifiers can include a Dex modifier, +5 if you are trained and more.
Step 3 - this stealth check is compared to the Passive Perception check of the target enemies, each has their own. A passive perception check is used when the enemy is not actively looking for you. The passive perception is a 10 plus their Perception modifier.

Fail by 1-9 points, the enemy knows what general direction you are in and about how far you are, but does not see you.
Fail by 10 or more point, the enemy knows exactly where you are.
Pass enemy is unaware of your presence. You have the combat advantage on the enemy.

In combat this is what this would look like. Erdan creeps up pair of orcs sitting by a fire. He uses his Stealth skill on his move action. He then roles a 16 and received a +10 modifier to Stealth that gives him a stealth check of 26. The orc’s passive perception is a 16. Erdan Stars with Deft strike allowing him to move 2 spaces and then attacking as a single standard action. Erdan will remain sheathed through the entire action and thus have the combat advantage on his target. This initiates a surprise round, only a single action can take place.

Create a diversion
In another scenario Edran desires to make a quick getaway. He uses a flask grenade to distract his enemy to hide. This requires that Erdan use a standard action and his place to hide is with in his movement.

Step1-Erdan makes a Bluff check vs. the enemy’s passive perception
Fail: enemy sees him
Pass: Role for Stealth check

Step2 Stealth check against passive perception for all enemies present
*You can hide behind your enemies back, if no other enemies are present.

Enemy Activity
If the enemy is actively looking for you, the make a active perception check, that means the role a 1d20 and add their perception modifier to it. This is done on their turn. Each enemy gets a perception check. Also if an enemy enters your square, you are no longer hidden.

Remaining Hidden
You must meet the following 3 conditions or you will need to complete a new stealth check.
1.Keep out of sight - you must have some degree of cover or concealment during your turn to remain sheathed
2.Remain quiet - Anything above a whisper can alert to enemy to your presence
3.Remail still- any movement above 2 squares (10 feet) will require you to make stealth check.

Modifiers:
-5 for movement above 2 squares
-10 for running