Eventually, all investigators have to face their fears and do battle with the mythos. Whenever an investigator enters combat with a monster, resolve the following steps, in order.
First, the alien nature of the mythos creature threatens to overwhelm the investigator’s mind. This is represented by a Horror check.
A Horror check is a skill check based on the investigator’s Will value, as adjusted by any special modifiers. This value is further modified by the monster’s horror rating (found in the lower-left corner of its combat side). The difficulty of this check is always 1 unless the monster has a special ability that states otherwise. If the investigator passes the check, usually nothing happens.
If the investigator fails the check, he loses the amount of Sanity shown underneath the monster’s horror rating. This is termed Horror damage. The player discards the appropriate number of Sanity tokens from his investigator sheet. An investigator reduced to zero Sanity tokens is driven insane.
A few monsters have the special Nightmarish ability. These monsters are so horrendous that the investigator loses some sanity from Horror damage even when passing a Horror check.
Fight or Flee
Next, the investigator must choose: He may either attempt to flee or fight the monster.
If he passes the check, he eludes the monster and the battle immediately ends. Both the investigator and the monster remain in the same location. If he fails the check, the monster deals its combat damage to the investigator and the battle continues (see “Monster Damage,” below).
If the investigator fights the monster, he makes a Combat check. A Combat check is a skill check using the investigator’s Fight value, as adjusted by any special bonuses they may have to combat, for instance from weapons or spells. This value is further modified by the monster’s combat rating (printed in the lower-right corner of its combat side). The difficulty of this check is equal to the monster’s toughness, which is represented by the number of “blood drop” icons that appear in the lower center of the monster’s combat side.
If the investigator passes the Combat check, he defeats the monster. The investigator’s player removes the marker from the board and places it in front of him as a monster trophy. If the investigator fails the check, the monster deals its combat damage to him.
Important: If a monster’s toughness is greater than 1, partial success has no effect on it. A monster must be completely defeated in one Combat check or it ignores all successes the investigator rolled.
Each time an investigator fails to evade or defeat a monster, the monster deals its combat damage to the investigator. The amount of combat damage a monster deals is printed below its combat rating as a group of red hearts. The investigator loses Stamina equal to this number. The player discards the appropriate number of Stamina tokens from his investigator sheet. An investigator reduced to zero Stamina tokens is knocked unconscious. Note that some monsters have abilities that add some special effect to their combat damage or take its place. For example, the Nightgaunt drops the investigator through the nearest open gate instead of causing the investigator to lose Stamina tokens.
If the investigator remains conscious, sane, and in the same space as the monster after this step is resolved, the combat continues. Return to step 2, Fight or Flee, and continue the combat until it is resolved.
Using Weapons and Spells in Combat
Investigators can gain a valuable edge in combat by using weapons. spells, or both. The biggest advantage of weapons is that they automatically grant bonuses on Combat checks - no additional skill checks are required to use them. However, Physical weapons grant only Physical Combat bonuses, which have no effect at all against many mythos monsters which have Physical Immunity and a lesser effect against those with Physical Resistance.
Spells, on the other hand, grant Magical Combat bonuses. These are effective against most monsters in Arkham Horror. An investigator must successfully cast a spell to gain its benefits (see Casting Spells). If an investigator fails to cast a spell, it provides no bonuses for the combat at all. In other words, spells are more powerful and versatile than weapons, but they are not always a sure thing.
Magical weapons are effective against most monsters, including those with Physical Immunity or Physical Resistance, but there are some monsters with Magical Immunity or Magical Resistance against which they are ineffective.
Weapon and Spell Hand Limits
There is a limitation on the number of weapons and spells an investigator may use at once. This limitation is represented by “hand” icons printed in the lower-left corner of each weapon and spell card. Each investigator may use any combination of weapons and spells and add their skill bonuses together, as long as their combined number of hand icons does not exceed two. Note that a spell requires the number of hands printed on the card, even if the investigator fails to cast it.
A spell or weapon that gives you a bonus (even one that says it lasts until the end of combat) only continues to give you the bonus while you devote the required number of hands to it. You can choose to switch weapons/spells in later combat rounds, but as soon as you “release” a spell or weapon, it stops working for you. Similarly, spells that are refreshed (such as at the beginning of each combat round in the final battle) cease to work and must be re-cast.
A few weapons or spells require no hands, and can be used in conjunction with up to two hands of other weapons or spells.
When a monster surprises your investigator, you may not evade it; you must fight the monster. You may not attempt to flee during the first round of a surprise combat.