Map Combat Rules

Hex Playmat Combat

Hex playmat combat adds a tactical grid layer to OpenRPG encounters, governing movement, positioning, and zone of control. One hex equals one metre.

Hex playmat combat places all combatants on a hex grid where position, movement budget, and threatened zones are tracked explicitly. This optional layer is used when precise tactical adjudication matters — ambushes, fortress assaults, ship boarding actions, or any encounter where flanking and positioning change outcomes.

One hex equals one metre. All distances in map combat — movement budgets, weapon reach, zone of control, forced movement, and spell or imbuement ranges — are expressed in hexes and read directly as metres.

Every combatant on the hex grid belongs to a faction, has a movement type, and starts each turn with a movement budget expressed in hexes. The GM tracks initiative order, records movement budgets, and advances turns manually.

Factions

Every combatant on the hex grid belongs to one of four factions that determine allegiance and zone of control interactions.

Faction determines whose zone of control affects a combatant. A combatant threatening an enemy creates a zone of control only against enemy-faction participants.

Movement Types

Each combatant is assigned a movement type before the encounter begins. Movement type determines which terrain conditions increase hex movement cost and which the combatant ignores entirely.

Movement type reflects the primary mode of travel for a creature or character. A combatant has one active movement type at a time, assigned during setup. Zone of control applies regardless of movement type — flying and swimming combatants are still threatened by armed enemies.

• A normal hex costs 1 hex of movement regardless of movement type.
• A combatant may only enter a hex if they can pay the full cost — movement remaining cannot go below zero.
• Forced movement ignores terrain costs unless the pushing effect says otherwise.

Movement Budget and Terrain

Each combatant begins their turn with a movement budget in hexes. Terrain type and movement type determine the cost to enter each hex.

At the start of a combatant's turn, their movement remaining is reset to their movement maximum. The GM spends movement in hex increments during the turn. Any unspent movement is lost when the next turn begins.

• Normal hex: costs 1 movement for all movement types.
• Difficult terrain hex: costs 2 movement for GROUND; costs 1 for FLYING and SWIMMING.
• Movement remaining can never go below zero — the GM must confirm a move is affordable before spending.
• Partial moves are allowed; a combatant may stop on any hex as long as movement remaining covers the cost to enter it.

Zone of Control (Threatening)

A threatening combatant exerts a zone of control over the hexes they can currently threaten, exhausting the movement of any enemy who enters those hexes through voluntary movement.

A combatant that is armed and engaged — ready to strike at anyone who moves through their reach — is marked as Threatening. Any enemy combatant who enters a hex currently threatened by that combatant through voluntary movement immediately exhausts all remaining movement for that move action. They may complete the move into the threatened hex, but cannot move further that turn.

• Threatening status is assigned by the GM to combatants that are armed, engaged, and positioned to strike.
• Threat is normally adjacent for ordinary melee weapons, but extends farther for weapons or creatures that legally threaten beyond adjacency.
• Zone of control only affects combatants of an opposing faction — a threatening PLAYER does not exhaust ALLY movement.
• The movement exhaustion occurs when the enemy enters the threatened hex, not when they start adjacent to it.
• A combatant that begins their turn already inside threatened space is not automatically exhausted; only movement into threatened space triggers ZoC.
• Flying and swimming combatants are still subject to zone of control from threatening enemies regardless of movement type.

Session Lifecycle

A combat encounter moves through three phases. The GM manages each transition.

• Combat begins when the GM calls it — once all combatants are placed and initiative is set.
• A combatant who joins mid-combat enters the initiative order at their initiative value and acts when their position next comes around.
• Combat ends when all opposing combatants are defeated, have fled, or the situation resolves without further exchanges.

Facing and Flanking

Combatants on the hex grid use facing to determine defended arcs, rear pressure, and flanking penalties.

Facing matters on the hex grid. Every combatant has a front, left, right, and rear orientation that helps determine which sides are defended cleanly and which angles are more vulnerable to coordinated pressure.

• For a standard one-hex combatant, the front covers the three forward-facing hex sides.
• The left and right each cover one side-facing hex.
• The rear covers the single back-facing hex.
• Combatants may rotate their facing during their own turn as part of ordinary positioning unless another rule prevents it.

Use only the strongest applicable positional penalty. Flank and rear penalties do not stack. Apply the penalty on the defender’s side of the resolution rather than as a raw attacker bonus.

Reach and Threatened Space

Weapon reach changes both attack distance and zone-of-control pressure on the hex grid.

Reach matters in OpenRPG hex combat. The weapon in hand determines not only how far a combatant can strike, but also how early they can project battlefield pressure into approaching space.

• Ordinary melee weapons threaten adjacent hexes.
• Long weapons such as polearms threaten at reach 2 unless the weapon profile says otherwise.
• A threatening combatant projects zone of control through the hexes they can legally threaten.
• Long weapons do not automatically attack both adjacent and reach-2 targets unless the weapon profile supports that.

This makes long weapons especially effective for holding lanes, checking approach, and supporting formations, while shorter weapons remain strongest in close pressure and tight scrums.

Disengage and Passing Through Pressure

Combatants may pass by danger without free strikes, but disengaging is the deliberate way to break melee pressure safely.

OpenRPG does not use attacks of opportunity or free melee strikes as the default punishment for movement. Passing by an engaged combatant is not the same as stopping to engage them.

• A combatant may pass through threatened space without being attacked just for transit.
• Zone of control shapes movement by exhausting the mover's remaining movement when they enter threatened space through voluntary movement.
• This zone-of-control exhaustion applies only the first time the combatant voluntarily enters threatened space during that turn.
• Forced movement does not trigger zone-of-control exhaustion, but still interacts with battlefield hazards unless a specific effect says otherwise.

Disengage is method-based rather than universal. The player should describe how space is being created, then choose the most relevant existing combat skill based on what the combatant is wielding and what they are best trained to do.

Players choose the method that best matches both their current weapon or equipment and the skill they are actually strongest in. Disengage should feel like creating an opening on the battlefield, not claiming a free movement exemption.

Large and Giant Creatures

Large creatures occupy multiple hexes and project threat from the edge of their footprint.

Size matters on the hex grid. Large and giant creatures should own visible space on the battlefield rather than behaving like standard one-hex bodies.

• Adjacency to any occupied hex counts as adjacency to the creature.
• Threat for multi-hex creatures is measured from the edge of the occupied footprint.
• A multi-hex creature may only move if its full new footprint fits legally in the destination space.