Gridless Combat

Here are Max’s suggested gridless combat rules:

“Round bases required” rule

  1. All miniatures are required to have round bases.  Note a cheap way to retrofit a base is to use double-sided tape or glue to attach the miniature to a washer of appropriate diameter.
  2. All round bases must be of appropriate diameter for scale used, e.g. 1" diameter bases for medium characters on scale of 1" = 5’. Large creatures that in a grid would consume 4 squares are required to be on bases of 2" in diameter.  Etc.

“Range is between center points” rule

  1. Range distances between minis are measured between the center points of both round bases. In practice, this means that you can calculate the range by measuring the distance between the closest edge of the two bases, and then add the radius of both minis. In the common case where both figures have 1" diameter bases, that means the range between the minis is equal to the distance between the two bases + 1/2" + 1/2."  This has the following nice property for melee attacks.  If the attacker has 5’ reach, and both the attacker and the target are figures on a 5’ = 1" base, then in order for the attacker to make a melee attack, the bases must touch.  This makes the common case, for determining melee reach, simply a matter of making sure that bases touch in order to be allowed to make a melee attack.
  2. For the common case of 5’ reach and attacker and defender are both on a 5’ base, to threaten attacks of opportunity, bases must touch
  3. In the common case (5’ reach and attacker and defender are both on 5’ base), a move that breaks touching base contact (by any distance), triggers Attack of Opportunity, unless it is a declared 5’ step in which case you are safe from the AoO but can only move up to 1" away.  Withdrawal is the
    other option, following the same principle.
  4. Any area spell effect that has the center point of the base of the target mini within “range” affects the figure.  Consider an example where a spell is cast with a radius of 20’ = 4" at a scattering of opponents on 5’ = 1" bases. The wizard marks the center point of the radius of the AoE. Since all the target minis have 1" bases, the wizard can take off 1/2" from his spell radius for an “effective touch radius.” So the wizard only needs to stretch a radius string 3 1/2". If the end of the radius string TOUCHES any of the target bases, they are in the AoE.

Advanced Rule: “Declare first, measure second”

This is an optional rule suitable for experienced players who have become familiarized with the process of gridless play and have begun to get a sense of ranges.

The general principle is “declare first, measure second”: that taking range measurements, of the battlefield, and stretching line of sight strings, or Area of Effect (AoE) radius circles or laying down AoE templates, or similar actions, are restricted player actions.  It can only be done by a player, on their turn in the initiative order. The action that the player character is going to take must be declared BEFORE taking measurements.  Once the action is declared, it cannot be changed.  Measurements, line-of-sight strings, etc. can only be performed to resolve the specified action, not for other purposes (no measurements to the benefit of the player coming up next in the initiative order for example).  It is possible that the declared action may fail because of range limitations, line of sight failures, cover, friendly fire, terrain, etc.  The DM arbitrates how a failed action is resolved.  The general principle of “declare first, measure second” serves two purposes:

  • It makes the combat more realistic in that you have to make on-the-fly guesses at ranges, and area of effects, or cover, open paths for charging, etc. just like your character does.  Combat is dynamic and fast and combatants are assumed to be moving around constantly and all action should be happening simultaneously in some sense, not static (we artificially break it down into turns), and characters have to make on-the-spot decisions in the hustle, bustle, and fog of war.  It makes the possibility of missing enemies by range, cover, and AoE mistakes and friendly fire more likely.  This will heighten risk, pressure, excitement, and realism and
  • It will greatly speed up combat.  Otherwise, players are likely to measure several different actions, to decide what they do, before doing it.

Examples of the general principle of “declare first, measure second”:

Spell casters and missile weapon users are required to declare their attack or spell and their target before measuring distances or running a line-of-sight string to determine cover or ability to hit target. They must declare the target figure on the board, or they must touch a point on the board to be the center of effect.  They may not measure circular area of effect with a radius string before declaring the spell cast and the target.

Similarly charging has to be declared before measuring distances or running a straight string to see if there is an unimpeded straight path to target not hitting any figures (friend or foe) or terrain features.  A fizzled charge because of misjudgement by the player basically moves the character along the line until hitting an obstacle.

Advanced Rule: “5 second countdown”

This is an optional rule suitable for experienced players who have become familiarized with the process of gridless play.

The DM imposes a 5 second countdown for each player to declare their action or forfeit their action and get bumped one person down in the initiative order (where they can get another 5 seconds to declare or get bumped again).  Although this may sound harsh it is realistic in that:

  1. each round of combat is supposed to be 6 seconds long in “real
    time” and
  2. players can do a lot of planning and thinking of their actions (and guessing distances and eyeballing line of sight (no strings allowed)) during previous player’s turns in the initiative order.  The initiative order is cyclical and predictable (and we should use an initiative board so everyone can at a glance see what is coming up and plan).  
  3. it adds realism that in combat people miss opportunities because they aren’t decisive and quick enough to act on an opportunity, and sit there hemming and hawing.

“DM can break rules” rule

The DM is not required to abide by the rules imposed on the players (most typically the 5 second countdown rule, but also potentially the “measure first” rule, but really any rule) although he’s expected to usually try and follow them in spirit if appropriate and he can manage it.  This is simply to recognize that the DM often has a lot, lot more to think about, manage, plan, and track, and as such is given greater leeway.

“Friendly Fire” Rules

The usual rules situational penalties to to-hit rolls for cover and firing into melee apply.  I think it is a cumulative minus 4 adjustment to hit for each (need to check).   In the common case of 5’ melee reach against an opponent figure with 5’ base, deciding if you are targeting into a melee is adjudicated by whether or not bases are touching.  In the simple case, if the attacker manages to hit despite the situational roll penalties, the attack is resolved as normal.  On a
miss, however, a simulation of what would realistically happen is based on a stretched line-of-sights string from attacker to target with hit resolutions resolved against cover or figures (friend or foe) along the path from attacker to target in order of the missile travel.  I suppose a simple mechanic for fast adjudication speed would be to use the original to hit roll (rather than reroll) and compare it to each obstacle in the path along the path.  AC for friend and foe alike can be compared for an earlier hit.  Cover could be adjudicated as hit depending on the numeric distance from hitting the target or something.  In a sense this can both benefit and detriment ranged attackers, in that as a benefit, if you fire into a cluster of foes you’re pretty like to hit something — maybe not your intended target, but something; and detriment that friendly fire incidents are more likely to happen.

References and further discussion

Some references that should provide background to these rules.  But a lot of the rules above are based on my prior experience of gridless combat.  Some of these references have pictures.

Gridless Combat

Kirin's Rise of the Runelords koboldstyle MaxRobinson