The multiplier method: scaling off your damages
The multiplier method is the industry's default approach. It takes your economic damages — medical bills and lost wages — and multiplies that total by a factor generally between 1.5 and 5, chosen based on injury severity, recovery time, and whether any permanent impairment is involved.
The per diem method: valuing each day
The per diem (Latin for "per day") method works differently. It assigns a specific dollar value to a single day of pain and suffering and multiplies that rate by the total number of days of documented recovery, tying the value directly to time rather than to the size of your medical bills.
Why the slight/gross question comes before either method
Most states ask a percentage question — was the claimant under 50% or 51% at fault? South Dakota asks something different entirely: was the claimant's fault "slight" compared to the defendant's "gross" negligence, under SDCL § 20-9-2. That's a threshold, all-or-nothing question the jury answers before either valuation method becomes relevant — if fault wasn't "slight," there's no noneconomic recovery to multiply or count by the day at all.
So the fault characterization comes first
Before investing effort in choosing between the multiplier and per diem methods for a South Dakota claim, it's worth understanding how a claimant's own conduct is likely to be characterized under the slight/gross standard — that qualitative judgment call can determine whether there's anything left to value at all.
Neither is required by South Dakota law
Both methods remain negotiating tools, not a formula South Dakota courts are required to apply. A jury retains discretion to award whatever amount it finds appropriate for noneconomic damages, once the slight/gross threshold is cleared — subject only to the malpractice cap when that type of claim is involved.