Lightweight Space Parasite vs. Colonial Marines

Colony Viat Sursum - prefall

I've been considering running a lite-hearted aliens-themed game akin to: I roll to see if I have shoes on.

Base Rules

1. Say what you do and roll a number of d6s.
2. If the sum of your roll is higher than the opposing roll (either another player or the DM), the thing you wanted to happen, happens.
3. The number of the d6s you roll is determined by the level of skill you have.
4. At start, you have only one skill: Do anything 1.
5. If you roll all sixes on your roll, you can get new skill one level higher than the one you used for the action. The skill must be a subset of what happened to you in the action (Say, Athletics 2 if you were climbing a wall, or Teeth of Biting 2 if you were eating a cake).
6. For every roll you fail, you get 1 XP.
7. XP can be used to change a die into a 6 for advancement purposes but not for success purposes.

Comments from rpg.stackexchange.com

• Note: When you gain a new skill from an action (bullet point 5), it won't necessarily have any relationship to the skill you used to perform that action.
• For example: Alice uses Jump 3 to try to jump a wooden fence, but fails and instead just crashes through it. Alice spends XP to get Breaking Things Embarrassingly 4 because it's a subset of what happened to her in the action (even if it has nothing to do with jumping).
• Bullet point 5 is often misread as saying the newer skill must be a specialisation of the previous skill, probably because we're prepared to see skill trees even when they're not there. This game doesn't have skill trees and is fine with weird new skills coming out of the blue.

Ideas for introducing roll-for-shoes

Extended Rules for Space Parasite vs Colonial Marines

1. Effective area of the spell or skill is only up to the square of the level.
2. Players can create their own party by converting bystanders/npcs, but they still start at level 1
3. For example eggs, crawlers, larvae, colonists, androids (even those who prefer the term "Artificial person"
4. Only one action per turn per person. Note that the gm can control several units based on an overall control rating equal to the number of live players.
5. Goal is to take over the colony
6. Damage delivered is equal to the skill level.
7. Damage disables skills (temporary until healed.) The target makes the choice. If damage is insufficient to cancel the skill, it is kept track of.
8. Healing magic/skill/tech delivered is equal to the skill level.
9. Actions that are a combination of effects, says vampirism, do so at a numeric level half the skill level (bloodsucking removes half skill level from target but adds half extra life (healing) to vampire).