Shadows over London is a round turn based strategy game set in a destroyed London which has been overrun by monsters from the lovecraftian horror genre. In this game the player controls five people who survived the initial attack. The goal is to use the survivors’ unique abilities strategically in order to help them (or as many of them as possible) to escape.

The core gameloop looks as followed:


Since the game is divided into turns the player can take as long as they want to decide what each survivor they control should do on their turn. Survivors can be controlled independently of each other. That means it is possible to perform some actions with one character, switch to another character and then finish the turn with the previous character. Each survivor has three actions they can take each turn.

These actions can be used for three different things:

  • Moving
  • Abilities
  • Items

Each survivor comes with two basic abilities:
Preparation & Attack

The Preparation-Ability is useful for when the player doesn’t want to potentially waste ammo on a bad shot but still has actions left on a character. This ability ends this characters turn but gives them a small boost to their aim and dodge values in their next turn.

The Attack-Ability functions as most would expect. After selecting it a target can be selected which is then attacked. If that target is on an adjacent tile it will be attacked in melee combat which guarantees a hit. If it is too far away for a melee attack but still within reach the character will fire a shot at the target, hitting it with a certain percent chance but always consuming ammo.

The Colour from out of Space

Attacking with probabilities

Unfortunately most players will not be very good at working with probabilities. To many it will feel unfair if they missed three 50% shots in a row. To avoid a feeling of frustration we came up with a few mechanics and tweaks to give players more control over the probabilities or to understand them more intuitively.

First of all the probabilities shown are not the real probabilities the game uses. They are always rounded down to the next 5% increment which simplifies the game a lot already. But they are also constantly 10% lower than the actual probabilities. This makes it seem like the player gets lucky more often than missing a shot. But if the player does miss a couple shots there is another mechanic that will ensure there won’t be too many missed shots in a row. Every time the player misses the real chance they had is put on a stack and when the sum of that stack exceeds 120% the next shot is a guaranteed hit. Every successful hit resets the stack so missing stays a real possibility. That also means that in many situations where the player misses a shot they considered as certain they will use another survivor to attack the same enemy with an uncertain probability. And having that second shot with a low probability hit creates a feeling in the player of “outsmarting” the randomness despite having bad luck. We also give each survivor a bonus 5% to their aim for every action they have left. All these advantages are only used by the survivors. Enemies always only calculate their moves and hits based on real, unaltered numbers.

The cultist enemy

Emergent Narrative

One of the most important aspects of Shadows over London was to create a feeling of suspense. When one of the survivors dies they are gone forever from the game. And to highlight that emotional impact we gave each of our survivors a voice to react to the player’s inputs and to what happens around them in the world. Since the survivors not only have a unique skillset and different stats but also a personality the impact of losing one of them can be quite severe.

The park environment

This is one of the reasons we put so much effort into minimising frustrating situations. But the game is built to be a tough challenge for the player and getting every single survivor to safety is a real accomplishment that requires clever use of the survivors’ abilities as well as excellent risk management.

Before we created the world in which the game takes place I created a timeline that reflected how we wanted a level to be paced. We could then draw quick sketches and quickly get into developing the level.

Useful Abilities

Finally I’d like to touch on the abilities the monsters and players can use. I designed 20 unique abilities for the survivor characters and 12 for the monsters. Because of Lovecraft’s historical context and personal believes it was very important to all of us to feature a diverse cast with subverted role expectations. We also find that in some of the abilities. Like the nurse for example: He has very defensive skills and not a lot of physical health, but through his medical training can find spots for a potentially lethal attack when engaging with an enemy in melee range. Some other abilities like the construction worker’s ability to function as a human shield to allies, or lay barbed wire to change the properties on the map are more in tune with that characters personality. There are many more abilities and most of them can be seen in the exemplary gameplay footage below.

Lastly I’d like to touch on the items. We added them as an additional way of creating randomness that affects the player positively. Being able to make a small detour but gain a potentially lifesaving item in the process turned out to be one of things that really helped players to feel like they had a good chance in face of total adversity. These items can provide useful buffs to stats, function as additional attacks, and in the case of spells even give the players powerful one time use abilities.

Gameplay Footage
A dead survivor character and a swarm enemy