Tactical Objectives in Trail of Cthulhu

Knowing that the Thing could surely overtake the Alert until steam was fully up, he resolved on a desperate chance; and, setting the engine for full speed, ran lightning-like on deck and reversed the wheel. There was a mighty eddying and foaming in the noisome brine, and as the steam mounted higher and higher the brave Norwegian drove his vessel head on against the pursuing jelly which rose above the unclean froth like the stern of a daemon galleon. The awful squid-head with writhing feelers came nearly up to the bowsprit of the sturdy yacht, but Johansen drove on relentlessly.

The Call of Cthulhu

The Trail of Cthulhu combat rules work perfectly well when dealing with small numbers of human-scale foes – a lone Deep One or Byakhee, a few cultists – but they’re less suited to coping with gigantic creatures like shoggoths, vampirish vapours or dark young, or hosts of horrors like ghoul packs or flocks of bat-things. Now, it’s perfectly reasonable to argue that such encounters are more the province of pure narrative, or out of keeping with the mood of the game, but sometimes – especially in Pulp adventures – you want to be able to blow up the shoggoth by luring it onto Professor Frank’s experimental electrical generator.

These rules are (very) loosely inspired by the Ashen Stars space combat system and the Yellow King RPG rules.

At the start of an encounter, the players collectively choose one of the starting goals (Retreat, Drive Away/Break Through, Hide, Wound, or Lure). They then make ability tests as normal, trying to rack up successes collectively to meet the number required by a goal.

Goal Format

Here’s the format for goals.

Description. What you’re trying to do achieve by pursuing this goal.

Leads-In: What goals you need to achieve before attempting this one.

Leads-Out: What goals you can try for after completing this one.

Successes Required: How many successes you need to achieve this goal.

Abilities: What General Abilities can be used to score successes. One successful General Ability test grants one success.

The difficulty for these tests depends on the monster you’re fighting. In general

Human-size foes: Difficulty 4

Huge creatures: Difficulty 5-6

Cyclopean monsters: Difficulty 6-7

Great Old Ones: Difficulty 8+

Abilities may be tagged asRisky or Vulnerable.

Special: Any special rules that apply to this goal.

Effect: What happens if the group achieve their goal.

Risky & Vulnerable

If a character uses a Risky ability, then if that character fails, the monster gets to make an attack on that character.

If a character uses a Vulnerable ability, then that character gets attacked by the monster after the ability test, regardless of the outcome of the test.

The monster can attack as many times as opportunities present themselves – if six investigators attempt something Risky and fail, the monster gets to make six attacks.

Defending Others

Instead of making an ability test to accrue successes, an investigator can defend another investigator. This requires a test of Scufflingor Shooting; a kind Keeper might also allow the use of Athletics orDriving in some circumstances. Defending others is Risky – if the defender fails the test, they get attacked by the monster.

Switching Goals

If you change goal midway through an attempt, you lose all your accumulated successes. You can only switch to a starting goal.

Investigative Spends

If the player can justify it, an investigative spend might allow:

A different general ability to be used to generate successes towards the goal (I use Physics to tune the radio into the star vampire’s frequency – now I can lure it with Electrical Repair)

Increase the number of successes yielded by a successful test (Can I use Chemistry for a bigger bang from these Explosives tests?)

Armour and Vulnerabilities

Some Mythos entities are incredibly tough, or even immune to some forms of attack. Others are unusually vulnerable to a particular weapon or substance. Adjust the Difficulty for attacks using Shooting, Scuffling or Weapons as follows:

The monster’s magically vulnerable to this attack: -2

Low armour, big gun: -1

Most attacks: +0

High armour or partial immunity: +1

Chances of injuring the monster are slim: +2

No chance of hurting monster: Ability cannot be used.

Example: (The Dunwich Horror) In the end the three men from Arkham—old, white-bearded Dr. Armitage, stocky, iron-grey Professor Rice, and lean, youngish Dr. Morgan—ascended the mountain alone. They began with the Hide goal, racking up some successes by trying to spot the invisible monster, then switched to Lure (“through the lenses were discernible three tiny figures, apparently running toward the summit as fast as the steep incline allowed.”) before finally attempting Banish on the mountain-top.

Tactical Goals

Flee

You’re trying to get the hell out of there! Everyone just turns and runs at top speed. It’s undignified, but it might keep you alive. Devil take the hindmost!

Leads-In: Any. You can switch to this goal at any time.

Leads-Out: –

Successes Required: Successes are tracked individually. The first character to escape needs one success, the second needs two successes, the third needs three and so forth. Add one to the total needed if a character’s bringing a non-combatant along.

Abilities: Risky: Fleeing, Athletics

Special: You can reroll a failed test if you describe how your panicked retreat leads to some misfortune – you drop your weapon, you fall over a cliff, you get separated from the rest of the company.

Effect: You escape. There are no guarantees about your condition or situation when you make your escape – you may fainting, or get lost in the wilderness, or suffer some other humiliation – but at least you’re out of immediate danger.

Retreat

You intend to retreat in good order, staying together and leaving nobody behind.

Leads-In: None

Leads-Out: If you switch to Flee, you can keep half your accrued successes.

Successes Required: Two per investigator.

Abilities: Risky:Athletics, Stealth, Stability, Riding (to maintain discipline)

Vulnerable:Fleeing

If the group’s in a vehicle, then add Vulnerable: Driving, Piloting (but successes count double)

Effect: The group escapes the encounter with the monster.

Hide

You try to observe the monster

Leads-In: None

Leads-Out: Retreat, Lure, Drive Away/Break Through

Successes Required: 0.

Abilities: Vulnerable: Shadowing, Sense Trouble, Preparedness

Special: You must move on from this goal once the enemy is aware of your presence.

Effect: You may apply half your successes from this goal to your next goal.

Drive Away/Break Through

You try to force your way past the enemy, or force the monster into briefly retreating.

Leads-In: None

Leads-Out: None or Wound

Successes Required: Target’s Health /4

Abilities: Risky:Shooting, Weapons

Vulnerable: Athletics, Scuffling

Special:Track the number of natural 6s rolled during ability tests. If the group wishes to immediately attempt the Wound or Hold Out goals after completing this goal, they start with one success in Wound or Hold Out for every six rolled.

Effect: The monster retreats. Add another d6 successes to the number required if the investigators try for the same goal again in a future encounter.

Wound

You attempt to actually damage the monster.

Leads-In: None

Leads-Out: Maim, Retreat

Successes Required: Target’s Health/4

Abilities: Risky:Shooting, Weapons

Vulnerable: Athletics, Scuffling

Special: If a character rolls a 1-2 on an ability test, their next action is automatically Vulnerable.

Effect: The monster’s hurt. This doesn’t affect the creature’s abilities, but it’s the first step in destroying the horror (and analysis of the ichor or blood spilled might provide vital clues).

Lure

You try to draw the monster towards a particular location.

Leads-In: None.

Leads-Out: Trap, Bind/Banish

Successes Required: 6

Abilities: Risky:Athletics, Shadowing, Riding

Effect: The monster follows the investigators to a particular location nearby.

Hold Out

You secure yourself in a safe, defensible place and try to hold out for as long as possible. This might involve barricading the entrances, securing all entry points, or trying to endure this monstrous siege.

Leads-In: Retreat, Drive Away/Break Through

Leads-Out: Trap

Successes Required: 4 per investigator

Abilities: Vulnerable:Electrical Repair,Mechanical Repair, Preparedness.

Effect: The investigators hold out until dawn, or until help arrives, or until the attackers depart.

Maim

You attempt to kill the monster. If dealing with a host of horrors, you try to slaughter the greater number of them.

Leads-In: Wound, Trap

Leads-Out: None

Successes Required: Target’s Health/2

Abilities: Risky:Shooting, Weapons, Explosives

Vulnerable: Athletics, Scuffling

Special: If a character rolls a 1-2 on an ability test, their next action is automatically Vulnerable and they cannot benefit from another investigator defending them.

Effect: The monster is destroyed, or at least discorporated.

Trap

You’re going to trap the monster in a physical or magical prison.

Leads-In: Lure, Hold Out

Leads-Out: Wound, Bind/Banish

Successes Required: 4; 6 if the monster is especially strong, fast, agile, can fly, or moves through alien dimensions; 8 if it falls into multiple categories

Abilities: Vulnerable:Athletics, Electrical Repair, Explosives, Magic, Mechanical Repair

Effect: The difficulty of tests in the next goal is reduced by 2.

Bind/Banish

You’re going to use eldritch sorcery or hypergeometry to dismiss the monster.

Leads-In: Lure, Trap.

Lure is only necessary if the monster can only be banished at a particular place (within a magical sigil, atop Sentinel Hill, in direct sunlight).

Trap is optional, but unless the monster is constrained, then it may be able to flee instead of being banished.

Leads-Out: What goals you can try for after completing this one.

Successes Required: Spell’s Inertia/2

Abilities: Vulnerable:Stability

Effect: As per the spell

Trail of Cthulhu is an award-winning 1930s horror roleplaying game by Kenneth Hite, produced under license from Chaosium. Whether you’re playing in two-fisted Pulp mode or sanity-shredding Purist mode, its GUMSHOE system enables taut, thrilling investigative adventures where the challenge is in interpreting clues, not finding them. Purchase Trail of Cthulhu, and its many supplements and adventures, in print and PDF at the Pelgrane Shop.