This Developer Blog is copied verbatim from the RuneScape website. It is copyrighted by Jagex.
It is written by Mod Pi and is dated 6 September 2016.
Anti-Walk & Debuffs Dev Blog

Hey all,

The Combat Council would like to talk about some core combat changes coming on Monday. These contain changes to a PvM tactic known as ‘walking,’ and to some items that debuff your enemies’ defence. Read on to find out what is changing and why.


For an NPC to attack a player, they need to be between their maximum attack range and the square directly adjacent to the player. If the player is stood under the NPC (i.e. on the same square), the NPC needs to move in order to attack the player. ‘Walking’ is the process of constantly moving under the NPC so that it gets stuck in a state of trying to stand adjacent to the player, thus never attacking.

Walking is skilful technique used by best PvM players, but it can detract from the intended difficulty of our top end bosses. Over the years, we’ve come up with different ways of countering it. In every case, though – be it Vorago’s stomp, Nex’s mad dance or Araxxor’s stun - they are band aids that don’t actually fix the original issue. What is worse is that they can trigger when you are not actually walking the NPC.

From Monday 12th September, a new way of preventing walking will be applied to the bosses that we don’t intend to be walked. This fix will simply allow the NPC to attack you while you’re stood under them. At the same time, the existing anti-walk mechanics - which so many of you dislike - will be removed.

The following NPCs will be changed as described above:

  • Rise of the Six
  • Dagannoth Kings
  • Kalphite Queen (including exiled)
  • Kalphite King
  • Vorago
  • Beastmaster Durzag
  • Araxxor/Araxxi
  • Nex
  • Corporeal Beast

All other NPCs and bosses will behave exactly as they did prior to the update. In the future, we will not be adding anti-walking mechanics, and will instead use the new method to counter it on bosses we feel need it.

Defence Debuffs

There are many ways in which we debuff your opponent, and one of the most powerful we have in our arsenal is to change the base hit chance modifier. To understand what this is you need to know the hit chance formula of:

Hit chance = base hit chance modifier * (attacker accuracy / defender defence)

The standard way of working out your base hit chance modifier is simply to look at both the attacker’s and defender’s style and work out who has the advantage. The base hit chances are:

  • Strong chance – i.e. magic vs melee – 65% hit chance
  • Same chance – i.e. magic vs magic – 55% hit chance
  • Weak chance – i.e. magic vs range – 45% hit chance

Your accuracy vs defence calculation on the right then turns into a ratio which inflates or deflates this number.

Currently, the most powerful item we have in game that can modify this base hit chance is Statius’s Warhammer, which adds 10% base hit chance, allowing its wielder to partially ignore the combat triangle. While this is intended, it has undermined some of the top bosses more than we are comfortable with, especially when stacked with other such boosts. For this reason, we are going to be changing the way in which this and other defence debuffs work.

When looking at a number we were comfortable with, we look at the ability Quake as a solid base line. Quake will add 2% to your base hit chance modifier for 15% of your adrenaline - so 7.5% adrenaline used per 1% base hit chance boost.

Compare this to Statius’s Warhammer, which offers 10% to your base hit chance modifier for 35% adrenaline - 3.5% adrenaline per 1% base hit chance boost. This is an obvious imbalance, and one that we want to address.

First we will be reducing how strong Statius’s Warhammer is by bringing the base hit chance offset down. To keep Statius’s Warhammer as the best debuff in game, we will also be reducing the base hit chance offset on other items that use this method.

Items that offset the base hit chance modifier will be affected in the following way:

  • Statius Wahammer - +5% to base hit chance modifier (down from +10%)
  • Dragon Hatchet - +3% to base hit chance modifier (down from +5%)
  • Barrelchest anchor (when debuffing defence) - +3% to base hit chance (down from +4%)
  • Bone dagger - +2% to base hit chance (down from +5%)
  • Bandos godbook passive - +3% to base hit chance (down from +5%) – note that we have also changed the Bandos godbook to use the same internal cooldown as the other books as a result. The internal cooldown is now 12s (down from 30s)

The following remain unchanged:

  • Quake – +2% to base hit chance
  • Guthix god staff - +2% to base hit chance

The debuffs shown above stack additively (but only one of each can be active per NPC) and will now cap at +10% to base hit chance. This allows us to keep using this method on new rewards without the worry of it getting too powerful and having to reduce numbers in the future.

These changes will be coming with the next update and we will monitor feedback after it release. It will allow high-end PvM to rely less on awkward or inconsistent mechanics in order to discourage extreme stat drains and strange player behaviour (walking).

Thanks for reading, and we look forward to further discussion.

Mod Pi & the Combat Council

The Combat Council is a part of the RuneScape development team that dedicates some of its time to trying to improve the health of both PvM and PvP. We are Mods Curse, Deg, Harrison, Shogun, Hunter, Pi, Daze, Ramen, Ryan, Manti, Ollie, Chaose and Timbo.
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