So, I’m still an idiot who can’t do anything model-related and I’ll be testing using wh40k tyranid models for aliens and Imperium models for humans. But I’m actually trying to basically just make a new code system for anything anyone would make up, be it Tremulous or any other setting. Granted, I am not that great at home brewing rules, but I try! 
Every model has an initiative stat. The players use their models actions by activating one of their models. Models with the highest initiative have to go first. Then players alternate between activating models. For example, player one acts with his initiative 4 model. Second player acts with hit initiative 4 model. Player one has 2 more models with ini 4, but the second player Has none. So player one acts with both his ini 4 models, and only then the second player may act with his ini 3 models.
To act with the model, it has to use all its actions. A model has two actions. The two actions must be declared simultaneously- so, if you say your model will shoot and move, it’ll move, but also will be able to fire during its move, at any point.
Actions are:
Move: move the model it’s movement stat.
Shoot: detailed in the shooting.
Charge: movement that will get the model into base
contact with another. Any movement that places two models in base contact is called a charge regardless of what it’s original purpose was.
Interact: if there are any activatable objects, it’s the action to use them, also interaction with buildings.
Take aim: add 2 to models accuracy for its round.
Go to ground: subtract from the accuracy of anyone shooting at this model till it’s next turn.
Shooting:
Pre-measuring range in the shooting is not allowed.
Every model and weapon has an accuracy value. To make a shooting attack roll 2d6. If the total is less or equal than accuracies of the gun and gunner summed with the modifiers, it’s a hit. Then damage is calculated by subtracting target’s Defense from weapon’s damage, to a minimum of 0.
Modifiers are:
Firing on the move:- 2
Target in half cover: 25% of the target model is covered:- 2
Full cover: 50% of the target are covered: - 4
Close combat:
Each model and melee weapon has a melee star.
When models are in base contact, roll a d6, that’s the amount of rounds of fighting. Then engaged fighters each throw a d6 and add their and their weapon’s melee stat. The fighter who wins gets a hit in. Deal damage as in shooting. Repeat this the number of rounds times. After that, the models may act normally in their turn, or stay. If both models stay, start combat anew.
Critical hits:
After a hit has been dealt in any phase, roll a d6. On a 5+ roll an additional d6 and look up the army’s crit table.
Hit and run: some models may make hit and run attacks. When this model charges, it’s always only one round of combat, then it may move it’s movement stat in any direction.
Buildings:
Each building may be created by a model with needed equipment. It takes the model two actions to build something. Then the buildings act as a fighter without the move stat and that are automatically hit in close combat.
