Speed Modifier
Speed modifiers change how much a combat unit can accomplish in a span of time, shifting the action economy in unit’s favor (or against it).
Haste vs. Slow
Speed modifiers are often expressed is terms of a [percentage change], i.e. 50% haste, 20% slow, etc., or as a direct multiplier (x1.5, x0.8); either case has the same UX issues outlined on multiplier.
With haste and slow being opposites, the game system must answer the question of how a haste effect and a slow effect work in combination. Some design options are:
- They cancel out mathematically, e.g.
- Haste gives +3 movement points but slow give -3 movement points, canceling out additivly
- Haste increases attacks by 100% (x2.0), slow decreases by 50% (x0.5), canceling out multiplictivly
- Haste suppresses or negates Slow and vice-versa, leaveing both in force but having no affect
- Haste overwrites (or dispells) Slow, and vice-versa, leaving the most recently cast in force.
- Can a short-term slow effect dispell a long-term haste effect? Is this fair?
- What if the slow and haste were of different magnitudes (i.e. the slow was lower magnitude and had lower cost)? Is this fair?
Examples
- Dungeons & Dragons 5th Edition: Haste and Slow do not dispell each other, and can both be active on a target at the same time. Some of the effects cancel out mathematically, but the other effects of Slow appear to dominate over Haste, leaving the target still partially slowed.
Implementation
Discrete Time - Unmeasured Turns
Unmeasured turn models have some difficulties with speed modifiers due to their coarse granularity. What does it mean to give 10% haste to a fighter when all sword swings are clocked to the same round of time? Or to slow a spell caster by 25%?
Extra/fewer turns
To give someone a multiple of 100% haste (double, triple, etc.), let them take more than one turn during the round, maybe immediately after their normal turn, or after other units have had their turn. To slow an enemy, the unit must skip every x turn. Either way, this is a huge advantage to one side or the other in the action economy and can be game breaking.
Giving a non-multiple of 100% is harder, but possible. The unit can be periodically be given an extra turn (every 2nd round, every 3rd round, etc.) or have a % chance of taking another turn.
Bonuses
Give the unit a few bonuses to expend during their turn. Maybe an extra swing for their attack, a whole extra attack (but nothing else) or an initiative bonus. Combat systems employing action points can give extra action points.
- In DnD 5th Edition, the Haste spell grants, among other bonuses, double movement rate and an extra limited action. http://deltasdnd.blogspot.com/2010/04/spells-through-ages-haste.html
Combinations
Combinations of the above strategies are also possible.
- Fighters in DnD 2nd Edition get 3/2 attacks per round for levels 7 - 14. (Is that an extra attack every other round? Different targets?)
- The haste abilities in Avadon grant the target a chance to make an additional attack (includes spells). Sometimes you get several turns in a row with two attacks, sometime several with just one.
Interactions
Giving extra turns has a consequence whne using turn-timef effects, specifically the extra turns will “consume” the effect faster. Round-timed effects will not have this consequence.