Simplified Basic Rules
Some of the rules in Icestorm are simplified compared to their full rules in Infinity N3.
Orders and Skill Types
Roughly speaking, Icestorm limits active troopers to performing the following Skill combinations:
- Move-BS Attack
- Move-CC Attack
- Discover-BS Attack
- Combat Jump
In the full rules, an Order allows the trooper to declare one or more actions but there are many types of actions that can be combined in an Order in different ways.
Skills Within an Order
An Order can combine two Short Movement Skills, a Short Movement Skill and a Short Skill, or can be an Entire Order Skill. See also: Structure of an Order
Short Movement Skills
A movement-related action that takes up half an Order. It can be combined with another Short Movement Skill or a Short Skill.
You can combine one Short Skill with a Short Movement Skill, but not with another Short Skill. So for example you can Move-Move or Move-BS Attack during an Order but you can't Dodge-BS Attack or BS Attack-BS Attack.
Entire Order Skills
As the name suggests, an Entire Order Skill takes up an entire Order so can't be combined with a Short Movement Skill or a Short Skill.
ARO Skills are actions that can be performed in reaction. Many Short Movement Skills and Short Skills are also ARO Skills, for example BS Attack, Dodge and Discover.
Automatic Skills and Deployment Skills
Automatic Skills are passive abilities that don't usually take up part of an Order (they're 'always on'). For example the Spektr's TO Camouflage which gives attackers a -6 BS MOD and also allows the Spektr to be in the TO Camo marker state.
Deployment Skills can be active or passive, so the Spektr's Infiltrate Skill is a passive ability used during Deployment, while the Akali's Combat Jump (actually Airborne Deployment Level 4: Combat Jump) is an active ability used when the trooper lands.
Declaring Orders and AROs
One of the most fundamental parts of Infinity is the Order Expenditure Sequence. Icestorm simplifies this down to 'Move, see if there are reactions, declare second Skill, roll dice'.
To expand this out, you actually:
Declare the first Skill of the Order, including declaring any movement paths, then measuring and moving the trooper, Declare any AROs by enemy troopers that have Line of Fire (LoF) or are within Zone of Control (ZoC) of the active trooper, Declare the second Skill of the Order (if the first wasn't an Entire Order Skill), again declaring, measuring and moving the trooper if it moved, Declare any 'new' AROs triggered by moving into LoF or ZoC of an enemy trooper that hasn't had a chance to react yet, Measure all ranges, work out MODs and roll all dice, Apply the effects of any Rolls, Finish the Order.
Although the Skills in the Order can be declared in any sequence, apart from any moves they will all be resolved simultaneously at the end of the Order. Because the two Skills of the Order are happening simultaneously, the active trooper can shoot from any point along their movement and can be shot at at any point along their movement, with the Rolls all happening at the end.
So don't think of a Move-BS Attack representing the trooper moving up to a firing position and then taking aim, but moving forwards and firing at the same time, while trying to outshoot their opponent. One of the most common uses of this is to use a Move to move up to a building corner and into LoF of an enemy model and then move back from the corner, the enemy trooper declares a Dodge or BS Attack (or some other ARO) and then your trooper declares a BS Attack for their second Skill, even though they're ending the Move out of sight.
For more details, see the Order Expenditure Sequence. If you're coming across timing issues it's always worth coming back to this page again, and remembering that all the actions in the Order are taking place at the same time.
Zone of Control
So what's this Zone of Control thing we just saw?
A trooper's Zone of Control represents the nearby surrounding area that the trooper is aware of even if they can't draw LoF and is a cylinder extending out 8" from the trooper's base. Reactive troopers get an ARO to any active trooper in their ZoC even without LoF, but these ZoC-triggered reactions are limited to Skills that don't need LoF, usually Change Facing (a limited type of Dodge that lets you turn on the spot) or Reset which is a defence against Hacking attacks.
Movement & the Prone State
The Common Skill Move has some additional restrictions, mainly that the trooper's base must be fully supported (no moving out over the edge of a roof) and that you can't move through gaps narrower than the trooper's base.
The General Movement Rules add extra rules that apply to all movement. Something that's completely new after Icestorm is the ability to go Prone at the start of a move. Prone is a Game State, or a condition that the trooper can be in - Unconscious being a prime examples. A trooper that is Prone halves their MOV values, but counts as only being 3mm high, the height of a normal base. This makes it possible to crawl along behind a wall or parapet without being seen, and also allows the trooper to claim Partial Cover when lying down on a surface higher than the firer. Note that troopers that fall Unconscious will usually enter the Prone state, so a trooper standing behind a wall or parapet will fall over, allowing a Doctor or Paramedic to safely crawl up to them and attempt to heal them.
In the full rules, to claim the Partial Cover bonuses, the trooper's Silhouette must be at least one-third obscured by the terrain piece they're touching. Being in cover doesn't just give a +3 MOD to the target's ARM, but also to their BTS if the attacker's weapon forces BTS Rolls rather than ARM Rolls.
In the full rules, each player is allowed to keep back one trooper (commonly called the 'reserve') to place after their opponent's deployment. See Initiative and Deployment for more details.
An additional basic rule not included in Icestorm is the Guts Roll.
Roughly speaking, if a trooper gets hit and survives, at the end of the Order they have to succeed at a WIP Roll to stay in position rather than ducking back. A failed Guts Roll gives the trooper get a 2" move to try and get into better cover, for example from being in the open to being in Partial Cover or from Partial Cover to Total Cover. If the 2" move isn't enough, the trooper will stay in place and drop Prone.
This means that even tough units in cover can be forced to duck back if you hit them, even if you don't manage to take them down.
IMPORTANT - movement from a failed Guts Roll can't be used to get closer to the attacker who forced the Guts Roll.