Wrecan's Guide to Improvised AttacksOne: The player describes the attack -- the DM converts that into mechanics.
Two: An improvised attack cannot be used as an opportunity action.
Three: An improvised attack is a weapon attack that always targets AC.
Four: An improvised attack inflicts Strength modifier damage (minimum 1) and a condition.
Five: An improvised attack targets only one creature and has no effect on a miss.
Six: The condition lasts no longer than the beginning of the target's next turn, or can be negated with a minor or move action, whichever makes the most sense to the DM.
Seven: The condition imposed cannot prevent the target from taking a standard action on its turn (i.e., dead, dominated, dying, helpeless, petrified, removed from play, stunned, unconscious, etc.)
That's it. They are pretty simple to remember, once you start using it. Tell your players about this ahead of time and you will see them trying to devise improvised attacks rather than at-wills.
Design ConcernsMy first concern when devising these guidelines was the idea that an improvised attack should be less effective than a basic attack in generic situations, but should be more effective than a basic attack in specific situations. If the improvised attack is too weak, the rule never gets used, and what's the point of an unused rule? If the improvised attack is too strong, then you'll never use a basic attack, and what's the point of an unused rule?
One: The reason I gave DM the final say on mechanics is to avoid gaming the rule. Moreover, the DM already has the final say on other improvsed actions, like stunts, so this is consistent with other aspects of 4e design. In truth, the DM and the player should work together for a satisfying interpretation, but you also don't want to drag the game down with negotiations.
Two: I prohibit using improvised attacks from being used as an opportunity attack because it becomes too easy to use that to lock an opponent down. Defenders, particularly, will use the action to trip a mark, making the mark more powerful than intended. Opportunity attacks are meant to punish, not prohibit, provocation of opportunity attacks.
Three: I make the improvised attack a weapon attack that targets AC so that the scalable attack and enhancement bonuses will apply. Targeting a defense other than AC will make attacks too easy, ad those defenses are usually 2 or 3 points lower than AC. I might allow the attack to substitute Stength for another Ability if they possess the Melee Training feat. I might allow for improvised attacks in other power sources, but only under a more advanced set of guidelines I will discuss in my next article.
Four: The reason I limit damage to Strength modifier damage is to prevent the improvised attack from replacing a melee attack. I would not allow other feats or abilities ot modify that amount. The Strength modifier damage is there to allow the player to take out a minion. That way, he won't be hesitant to use an improvised attack against a minion, for fear that he wasted it on a minion.
Five: I limit the attack to one target and forbid damage on a miss to keep the improvised action from surpassin a basic attack, which also targets only one creature and does no damage on a miss.
Six: I limit the duration to the beginning of the target's next turn or require an action tax to limit the power, but also to add a tactical element. For the most part, an improvised attack will only hamper the target from making opportunity actions or cause the target to grant combat advantage. Both results make the improvised action useful. However, it the target must spend an action (minor or move) to remove a condition, it might slow them down during their turn. But in no event will it prevent a target from making some sort of attack on its turn as a standard action.
Seven: The list of banned conditions is also designed to insure that the target is not prevented from taking a standard action on its next turn.
One: The PC drops a tapestry on the NPC, rendering the NPC blind until it uses a minor action to remove the tapestry.
Two: The PC causes the NPC to drop an item it holds in the NPC's square. The NPC can pick it up with a minor action. An NPC who is teleported or forcibly moved from the square makes a saving throw to keep the item in the destination square.
Three: The PC pushes the NPC backwards up to three squares, but not into a zone or difficult terrain.
Four: The PC trips the NPC. It requires a move action to stand.
Five: The PC tosses debris and junk in the NPC's square, requiring the NPC to spend a minor action clearing the square before shifting.
Six: The PC slams the NPC's helmet, dazing the NPC until the beginning of the NPC's next turn.
Seven: The PC spins the NPC around, momentarily disorienting the NPC. It grants combat advantage until the beginning of its next turn.
In my next article, I'll describe my guidelines for converting Encounter and Daily attacks into more powerful improvised attacks not limited to weapon-based attacks.